A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
I had the exact same problem and - after quite a bit of analysis - I reached the following conclusion
The metadata message appears if :
- The list contains a people column
- That column is required
- The column is not part of the selected view
- The column is set to be displayed as Name (with presence)
If you don't want the column in the view you can change the display to 'Name' and the missing metadata warning disappears.
This clearly seems to be a bug to me ;-)