diff --git a/app/assets/javascripts/diffs/store/getters.js b/app/assets/javascripts/diffs/store/getters.js
index 1fc2a684e951b1f119bc0ec32ac4ac1591cbaee6..dec3f87b03ef5787969b3c3ceeabbe71b448765a 100644
--- a/app/assets/javascripts/diffs/store/getters.js
+++ b/app/assets/javascripts/diffs/store/getters.js
@@ -156,16 +156,16 @@ export const diffLines = (state) => (file, unifiedDiffComponents) => {
   );
 };
 
-export function suggestionCommitMessage(state) {
+export function suggestionCommitMessage(state, _, rootState) {
   return (values = {}) =>
     computeSuggestionCommitMessage({
       message: state.defaultSuggestionCommitMessage,
       values: {
-        branch_name: state.branchName,
-        project_path: state.projectPath,
-        project_name: state.projectName,
-        username: state.username,
-        user_full_name: state.userFullName,
+        branch_name: rootState.page.mrMetadata.branch_name,
+        project_path: rootState.page.mrMetadata.project_path,
+        project_name: rootState.page.mrMetadata.project_name,
+        username: rootState.page.mrMetadata.username,
+        user_full_name: rootState.page.mrMetadata.user_full_name,
         ...values,
       },
     });
diff --git a/changelogs/unreleased/tor-defect-overview-placeholder-message-diffs-new-data-source.yml b/changelogs/unreleased/tor-defect-overview-placeholder-message-diffs-new-data-source.yml
new file mode 100644
index 0000000000000000000000000000000000000000..d602bad9d4e9f54e7f9305aa3bb86e8784cd0512
--- /dev/null
+++ b/changelogs/unreleased/tor-defect-overview-placeholder-message-diffs-new-data-source.yml
@@ -0,0 +1,6 @@
+---
+title: Hydrate some of the variables in the Overview tab suggestion commit placeholder
+  by switching the Diffs data source for it
+merge_request: 57419
+author:
+type: changed
diff --git a/spec/frontend/diffs/store/getters_spec.js b/spec/frontend/diffs/store/getters_spec.js
index 04606b486622901e6843520768799ad3bd61f191..2e3a66d5b012bf86e190dbdc4b22845de177527f 100644
--- a/spec/frontend/diffs/store/getters_spec.js
+++ b/spec/frontend/diffs/store/getters_spec.js
@@ -377,32 +377,40 @@ describe('Diffs Module Getters', () => {
   });
 
   describe('suggestionCommitMessage', () => {
+    let rootState;
+
     beforeEach(() => {
       Object.assign(localState, {
         defaultSuggestionCommitMessage:
           '%{branch_name}%{project_path}%{project_name}%{username}%{user_full_name}%{file_paths}%{suggestions_count}%{files_count}',
-        branchName: 'branch',
-        projectPath: '/path',
-        projectName: 'name',
-        username: 'user',
-        userFullName: 'user userton',
       });
+      rootState = {
+        page: {
+          mrMetadata: {
+            branch_name: 'branch',
+            project_path: '/path',
+            project_name: 'name',
+            username: 'user',
+            user_full_name: 'user userton',
+          },
+        },
+      };
     });
 
     it.each`
-      specialState              | output
-      ${{}}                     | ${'branch/pathnameuseruser userton%{file_paths}%{suggestions_count}%{files_count}'}
-      ${{ userFullName: null }} | ${'branch/pathnameuser%{user_full_name}%{file_paths}%{suggestions_count}%{files_count}'}
-      ${{ username: null }}     | ${'branch/pathname%{username}user userton%{file_paths}%{suggestions_count}%{files_count}'}
-      ${{ projectName: null }}  | ${'branch/path%{project_name}useruser userton%{file_paths}%{suggestions_count}%{files_count}'}
-      ${{ projectPath: null }}  | ${'branch%{project_path}nameuseruser userton%{file_paths}%{suggestions_count}%{files_count}'}
-      ${{ branchName: null }}   | ${'%{branch_name}/pathnameuseruser userton%{file_paths}%{suggestions_count}%{files_count}'}
+      specialState                | output
+      ${{}}                       | ${'branch/pathnameuseruser userton%{file_paths}%{suggestions_count}%{files_count}'}
+      ${{ user_full_name: null }} | ${'branch/pathnameuser%{user_full_name}%{file_paths}%{suggestions_count}%{files_count}'}
+      ${{ username: null }}       | ${'branch/pathname%{username}user userton%{file_paths}%{suggestions_count}%{files_count}'}
+      ${{ project_name: null }}   | ${'branch/path%{project_name}useruser userton%{file_paths}%{suggestions_count}%{files_count}'}
+      ${{ project_path: null }}   | ${'branch%{project_path}nameuseruser userton%{file_paths}%{suggestions_count}%{files_count}'}
+      ${{ branch_name: null }}    | ${'%{branch_name}/pathnameuseruser userton%{file_paths}%{suggestions_count}%{files_count}'}
     `(
       'provides the correct "base" default commit message based on state ($specialState)',
       ({ specialState, output }) => {
-        Object.assign(localState, specialState);
+        Object.assign(rootState.page.mrMetadata, specialState);
 
-        expect(getters.suggestionCommitMessage(localState)()).toBe(output);
+        expect(getters.suggestionCommitMessage(localState, null, rootState)()).toBe(output);
       },
     );
 
@@ -417,7 +425,9 @@ describe('Diffs Module Getters', () => {
     `(
       "properly overrides state values ($stateOverrides) if they're provided",
       ({ stateOverrides, output }) => {
-        expect(getters.suggestionCommitMessage(localState)(stateOverrides)).toBe(output);
+        expect(getters.suggestionCommitMessage(localState, null, rootState)(stateOverrides)).toBe(
+          output,
+        );
       },
     );
 
@@ -431,7 +441,9 @@ describe('Diffs Module Getters', () => {
     `(
       "fills in any missing interpolations ($providedValues) when they're provided at the getter callsite",
       ({ providedValues, output }) => {
-        expect(getters.suggestionCommitMessage(localState)(providedValues)).toBe(output);
+        expect(getters.suggestionCommitMessage(localState, null, rootState)(providedValues)).toBe(
+          output,
+        );
       },
     );
   });
diff --git a/spec/frontend/notes/components/note_body_spec.js b/spec/frontend/notes/components/note_body_spec.js
index 4922de987fa8a312711bbf3e0f23803febcef4fe..40251244423bff49f424f05f511a33b7941366a2 100644
--- a/spec/frontend/notes/components/note_body_spec.js
+++ b/spec/frontend/notes/components/note_body_spec.js
@@ -81,14 +81,21 @@ describe('issue_note_body component', () => {
             state: {
               defaultSuggestionCommitMessage:
                 '%{branch_name}%{project_path}%{project_name}%{username}%{user_full_name}%{file_paths}%{suggestions_count}%{files_count}',
-              branchName: 'branch',
-              projectPath: '/path',
-              projectName: 'name',
-              username: 'user',
-              userFullName: 'user userton',
             },
             getters: { suggestionCommitMessage },
           },
+          page: {
+            namespaced: true,
+            state: {
+              mrMetadata: {
+                branch_name: 'branch',
+                project_path: '/path',
+                project_name: 'name',
+                username: 'user',
+                user_full_name: 'user userton',
+              },
+            },
+          },
         },
       });