What’s New in Microsoft Teams | April 2023

With "old" teams, we could use Group Policy Preferences to drop custom backgrounds into people's profiles in the Backgrounds\Uploads Folder. 

The location for backgrounds appears to have moved to %localappdata%\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\MSTeams\Backgrounds\Uploads but when files are copied in there, they're ignored. I'm guessing there's some other reference to it elsewhere, either registry, or config file.  

How do we achieve this with "new" teams? This is an important function for corporate customers.