Message center post flyouts will have a high-level summary and a large flyout view with a separate metadata section on the right side. The changes will roll out in mid-February 2024 for Targeted Release and early March 2024 for Standard Release. Admins will notice the change on the flyout, and no preparation is required.
Applies to: Microsoft 365 suite
Source: mc.merill.net — data via Merill Fernando's open archive (MIT).