Is this v11?

EDIT: NVM you specified v10. I'll look into both versions. If it's in v10 it's probably in v11 too.

I looked into this. It seems to be an issue with addon_installed cache, but all logic points to the cache getting cleared by the setup wizard.

I'm not going to put any more time into this as it's a complicated issue with a very trivial negative outcome (the messages seem to clear themselves after a page hit or two anyway).