The original "own goal" is that "Office app" was a Windows Phone 7/Windows 8 application no one used called something boring like "Preview" or "Document Hub" around the time OneDrive was still being called SkyDrive from the Windows Phone "Hub app" era. The app was basically just an MRU view of SkyDrive filtered to Word/Excel/PowerPoint documents.
Renaming that app "Office app" didn't do much to explain what it was for or what it was good at, especially with the confusion of "Office suite" and "Office app". (Some of that seemingly intentional with "Office app" trying to be a "Start Here" for Office documents.) I think that rename was worse than the new one.
With the rename to "Microsoft 365 Copilot app" there's actually new features and some idea of what the app is now for ("doing LLM things while wearing a corporate document fursona"). It's a dumb name, but a dumb name for an app that's a little less dumb.
Renaming that app "Office app" didn't do much to explain what it was for or what it was good at, especially with the confusion of "Office suite" and "Office app". (Some of that seemingly intentional with "Office app" trying to be a "Start Here" for Office documents.) I think that rename was worse than the new one.
With the rename to "Microsoft 365 Copilot app" there's actually new features and some idea of what the app is now for ("doing LLM things while wearing a corporate document fursona"). It's a dumb name, but a dumb name for an app that's a little less dumb.