Forcing each team to do (or approve!) the update has nothing to do with a shared repository, it's just what limits and requirements you've added on top of your

Forcing each team to do (or approve!) the update has nothing to do with a shared repository, it's just what limits and requirements you've added on top of your repo(s). A for loop over N repos and an automated commit in each one is perfectly achievable. If you want consistency so you can automate stuff, require consistency.