[ncmncm]

Or, just leave everything in place, always, and have the other code ignore the annotations for exactly as long as the repo is private.

[munk-a]

Just FYI - you can star private repositories so it's not quite that simple. You'd need to determine if the starring aligns with permissions... but I think it's still relatively reasonable.

[ncmncm]

Ok, then have a separate button: "Delete all 54,000 stars on this repo", completely independent of public/private.