Microsoft is working on anall-new Outlook for Windows, based on the Outlook.com web app.
The official Microsoft 365 Roadmap has been updated with a listing for a new feature in development for Outlook.
The feature is expected to start rolling out in June 2023.
This feature will be turned off by default for commercial customers.
The new Outlook iscurrently in public preview, with no confirmed timeline for a final rollout.
Source:Microsoft 365 Roadmap