diff --git a/app/serializers/merge_request_widget_entity.rb b/app/serializers/merge_request_widget_entity.rb
index 797213e2600..e46b269ea35 100644
--- a/app/serializers/merge_request_widget_entity.rb
+++ b/app/serializers/merge_request_widget_entity.rb
@@ -151,6 +151,10 @@ class MergeRequestWidgetEntity < Grape::Entity
       can?(current_user, :create_pipeline, merge_request.source_project)
   end
 
+  def use_merge_base_with_merged_results?
+    object.actual_head_pipeline&.merge_request_event_type == :merged_result
+  end
+
   def head_pipeline_downloadable_path_for_report_type(file_type)
     object.head_pipeline&.present(current_user: current_user)
       &.downloadable_path_for_report_type(file_type)
@@ -161,11 +165,6 @@ class MergeRequestWidgetEntity < Grape::Entity
       &.downloadable_path_for_report_type(file_type)
   end
 
-  def use_merge_base_with_merged_results?
-    Feature.enabled?(:merge_base_pipelines, object.target_project) &&
-      object.actual_head_pipeline&.merge_request_event_type == :merged_result
-  end
-
   def merge_base_pipeline_downloadable_path_for_report_type(file_type)
     object.merge_base_pipeline&.present(current_user: current_user)
       &.downloadable_path_for_report_type(file_type)
diff --git a/app/views/projects/merge_requests/_mr_title.html.haml b/app/views/projects/merge_requests/_mr_title.html.haml
index b56e2c3f985..7fe91fb6560 100644
--- a/app/views/projects/merge_requests/_mr_title.html.haml
+++ b/app/views/projects/merge_requests/_mr_title.html.haml
@@ -41,7 +41,7 @@
           - if can_reopen_merge_request
             %li{ class: merge_request_button_visibility(@merge_request, false) }
               = link_to 'Reopen', merge_request_path(@merge_request, merge_request: { state_event: :reopen }), method: :put, class: 'reopen-mr-link', title: 'Reopen merge request'
-          - unless current_user == @merge_request.author
+          - unless @merge_request.merged? || current_user == @merge_request.author
             %li= link_to 'Report abuse', new_abuse_report_path(user_id: @merge_request.author.id, ref_url: merge_request_url(@merge_request))
 
       - if can_update_merge_request
diff --git a/app/views/shared/issuable/_close_reopen_button.html.haml b/app/views/shared/issuable/_close_reopen_button.html.haml
index 8365bc6f863..3453db9f209 100644
--- a/app/views/shared/issuable/_close_reopen_button.html.haml
+++ b/app/views/shared/issuable/_close_reopen_button.html.haml
@@ -21,5 +21,6 @@
     - else
       = render 'shared/issuable/close_reopen_report_toggle', issuable: issuable, warn_before_close: add_blocked_class
   - else
-    = link_to _('Report abuse'), new_abuse_report_path(user_id: issuable.author.id, ref_url: issuable_url(issuable)),
-              class: 'd-none d-md-block btn btn-grouped btn-close-color', title: _('Report abuse')
+    - unless issuable.is_a?(MergeRequest) && issuable.merged?
+      = link_to _('Report abuse'), new_abuse_report_path(user_id: issuable.author.id, ref_url: issuable_url(issuable)),
+                class: 'd-none d-md-block btn btn-grouped btn-close-color', title: _('Report abuse')
diff --git a/changelogs/unreleased/271589-report-abuse-on-merged-mr.yml b/changelogs/unreleased/271589-report-abuse-on-merged-mr.yml
new file mode 100644
index 00000000000..aef591da54a
--- /dev/null
+++ b/changelogs/unreleased/271589-report-abuse-on-merged-mr.yml
@@ -0,0 +1,5 @@
+---
+title: Remove "Report abuse" button from a merged Merge Request
+merge_request: 46031
+author: Takuya Noguchi
+type: fixed
diff --git a/changelogs/unreleased/remove-merge-base-pipelines-feature-flag.yml b/changelogs/unreleased/remove-merge-base-pipelines-feature-flag.yml
new file mode 100644
index 00000000000..1f39fe81000
--- /dev/null
+++ b/changelogs/unreleased/remove-merge-base-pipelines-feature-flag.yml
@@ -0,0 +1,5 @@
+---
+title: Use updated base report for CodeQuality MergeRequest widdget
+merge_request: 46384
+author:
+type: changed
diff --git a/config/feature_flags/development/merge_base_pipelines.yml b/config/feature_flags/development/merge_base_pipelines.yml
deleted file mode 100644
index 4f57ca556f1..00000000000
--- a/config/feature_flags/development/merge_base_pipelines.yml
+++ /dev/null
@@ -1,7 +0,0 @@
----
-name: merge_base_pipelines
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/44648
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/263724
-type: development
-group: group::testing
-default_enabled: false
diff --git a/doc/.vale/gitlab/AlertBoxCaution.yml b/doc/.vale/gitlab/AlertBoxCaution.yml
index 9e3bbeaa4e0..49d4dc62ab5 100644
--- a/doc/.vale/gitlab/AlertBoxCaution.yml
+++ b/doc/.vale/gitlab/AlertBoxCaution.yml
@@ -1,7 +1,7 @@
 ---
 # Error: gitlab.AlertBoxCaution
 #
-# Makes sure DANGER: alert boxes follow standard formatting.
+# Makes sure CAUTION: alert boxes follow standard formatting.
 #
 # For a list of all options, see https://errata-ai.gitbook.io/vale/getting-started/styles
 extends: substitution
diff --git a/doc/.vale/gitlab/CurlStringsQuoted.yml b/doc/.vale/gitlab/CurlStringsQuoted.yml
index af7f85e2a4d..a09c3fbfb51 100644
--- a/doc/.vale/gitlab/CurlStringsQuoted.yml
+++ b/doc/.vale/gitlab/CurlStringsQuoted.yml
@@ -1,7 +1,7 @@
 ---
 # Warning: gitlab.CurlStringsQuoted
 #
-# Ensures all codeblocks using curl quote any URL strings.
+# Ensures all code blocks using curl quote any URL strings.
 #
 # For a list of all options, see https://errata-ai.gitbook.io/vale/getting-started/styles
 extends: existence
diff --git a/doc/.vale/gitlab/VersionText.yml b/doc/.vale/gitlab/VersionText.yml
index e0180a3965c..e59b936ae3f 100644
--- a/doc/.vale/gitlab/VersionText.yml
+++ b/doc/.vale/gitlab/VersionText.yml
@@ -1,8 +1,17 @@
 ---
 # Error: gitlab.VersionText
 #
-# Checks for use of some of the top misused terms at GitLab.
-# For substitutions only flagged as warnings, see SubstitutionWarning.yml
+# Checks that version text is formatted correctly.
+#
+# Specifically looks for either of the following that is immediately followed on the next line
+# by content, which will break rendering:
+#
+# - `> Introduced` (version text without a link)
+# - `> [Introduced` (version text with a link)
+#
+# Because it excludes `-`, it doesn't look for multi-line version text, for which content
+# immediately on the next line is ok. However, this will often highlight where multi-line version
+# text is attempted without `-` characters.
 #
 # For a list of all options, see https://errata-ai.gitbook.io/vale/getting-started/styles
 extends: existence
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index 22ae8ffbc6c..2bb773aa13e 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -4853,9 +4853,6 @@ msgstr ""
 msgid "Cannot enable shared runners because parent group does not allow it"
 msgstr ""
 
-msgid "Cannot find user key."
-msgstr ""
-
 msgid "Cannot have multiple Jira imports running at the same time"
 msgstr ""
 
diff --git a/spec/features/issuables/close_reopen_report_toggle_spec.rb b/spec/features/issuables/close_reopen_report_toggle_spec.rb
index f0c994420ac..867d2ff7aae 100644
--- a/spec/features/issuables/close_reopen_report_toggle_spec.rb
+++ b/spec/features/issuables/close_reopen_report_toggle_spec.rb
@@ -105,6 +105,7 @@ RSpec.describe 'Issuables Close/Reopen/Report toggle' do
   end
 
   context 'on a merge request' do
+    let(:container) { find('.detail-page-header-actions') }
     let(:project) { create(:project, :repository) }
     let(:issuable) { create(:merge_request, source_project: project) }
 
@@ -120,24 +121,47 @@ RSpec.describe 'Issuables Close/Reopen/Report toggle' do
 
       it_behaves_like 'an issuable close/reopen/report toggle'
 
+      context 'when the merge request is closed' do
+        let(:issuable) { create(:merge_request, :closed, source_project: project) }
+
+        it 'shows both the `Edit` and `Reopen` button' do
+          expect(container).to have_link('Edit')
+          expect(container).not_to have_button('Report abuse')
+          expect(container).not_to have_button('Close merge request')
+          expect(container).to have_link('Reopen merge request')
+        end
+
+        context 'when the merge request author is the current user' do
+          let(:issuable) { create(:merge_request, :closed, source_project: project, author: user) }
+
+          it 'shows both the `Edit` and `Reopen` button' do
+            expect(container).to have_link('Edit')
+            expect(container).not_to have_link('Report abuse')
+            expect(container).not_to have_selector('button.dropdown-toggle')
+            expect(container).not_to have_button('Close merge request')
+            expect(container).to have_link('Reopen merge request')
+          end
+        end
+      end
+
       context 'when the merge request is merged' do
         let(:issuable) { create(:merge_request, :merged, source_project: project) }
 
-        it 'shows only the `Report abuse` and `Edit` button' do
-          expect(page).to have_link('Report abuse')
-          expect(page).to have_link(exact_text: 'Edit')
-          expect(page).not_to have_button('Close merge request')
-          expect(page).not_to have_button('Reopen merge request')
+        it 'shows only the `Edit` button' do
+          expect(container).to have_link(exact_text: 'Edit')
+          expect(container).not_to have_link('Report abuse')
+          expect(container).not_to have_button('Close merge request')
+          expect(container).not_to have_button('Reopen merge request')
         end
 
         context 'when the merge request author is the current user' do
           let(:issuable) { create(:merge_request, :merged, source_project: project, author: user) }
 
           it 'shows only the `Edit` button' do
-            expect(page).to have_link('Report abuse')
-            expect(page).to have_link(exact_text: 'Edit')
-            expect(page).not_to have_button('Close merge request')
-            expect(page).not_to have_button('Reopen merge request')
+            expect(container).to have_link(exact_text: 'Edit')
+            expect(container).not_to have_link('Report abuse')
+            expect(container).not_to have_button('Close merge request')
+            expect(container).not_to have_button('Reopen merge request')
           end
         end
       end
@@ -154,10 +178,10 @@ RSpec.describe 'Issuables Close/Reopen/Report toggle' do
       end
 
       it 'only shows a `Report abuse` button' do
-        expect(page).to have_link('Report abuse')
-        expect(page).not_to have_button('Close merge request')
-        expect(page).not_to have_button('Reopen merge request')
-        expect(page).not_to have_link(exact_text: 'Edit')
+        expect(container).to have_link('Report abuse')
+        expect(container).not_to have_button('Close merge request')
+        expect(container).not_to have_button('Reopen merge request')
+        expect(container).not_to have_link(exact_text: 'Edit')
       end
     end
   end
diff --git a/spec/serializers/merge_request_widget_entity_spec.rb b/spec/serializers/merge_request_widget_entity_spec.rb
index 7179ce08896..3f7d5542ae8 100644
--- a/spec/serializers/merge_request_widget_entity_spec.rb
+++ b/spec/serializers/merge_request_widget_entity_spec.rb
@@ -106,29 +106,16 @@ RSpec.describe MergeRequestWidgetEntity do
       let(:merge_base_job_id) { merge_base_pipeline.builds.first.id }
 
       it 'has head_path and base_path entries' do
-        expect(subject[:codeclimate][:head_path]).to be_present
-        expect(subject[:codeclimate][:base_path]).to be_present
+        expect(subject[:codeclimate][:head_path]).to include("/jobs/#{generic_job_id}/artifacts/download?file_type=codequality")
+        expect(subject[:codeclimate][:base_path]).to include("/jobs/#{generic_job_id}/artifacts/download?file_type=codequality")
       end
 
       context 'on pipelines for merged results' do
         let(:pipeline) { create(:ci_pipeline, :merged_result_pipeline, :with_codequality_report, project: project) }
 
-        context 'with merge_base_pipelines enabled' do
-          it 'returns URLs from the head_pipeline and merge_base_pipeline' do
-            expect(subject[:codeclimate][:head_path]).to include("/jobs/#{generic_job_id}/artifacts/download?file_type=codequality")
-            expect(subject[:codeclimate][:base_path]).to include("/jobs/#{merge_base_job_id}/artifacts/download?file_type=codequality")
-          end
-        end
-
-        context 'with merge_base_pipelines disabled' do
-          before do
-            stub_feature_flags(merge_base_pipelines: false)
-          end
-
-          it 'returns URLs from the head_pipeline and base_pipeline' do
-            expect(subject[:codeclimate][:head_path]).to include("/jobs/#{generic_job_id}/artifacts/download?file_type=codequality")
-            expect(subject[:codeclimate][:base_path]).to include("/jobs/#{generic_job_id}/artifacts/download?file_type=codequality")
-          end
+        it 'returns URLs from the head_pipeline and merge_base_pipeline' do
+          expect(subject[:codeclimate][:head_path]).to include("/jobs/#{generic_job_id}/artifacts/download?file_type=codequality")
+          expect(subject[:codeclimate][:base_path]).to include("/jobs/#{merge_base_job_id}/artifacts/download?file_type=codequality")
         end
       end
     end