[dethstar]

I guess it depends how they worked it in. Is it in the app permission requesting code? Then yeah, app would need to upgrade their api level. Is it on the OS level, and they'll do something like just give null/useless data when you deny the permisson? Then it wouldn't matter.

[CountSessine]

That's how cyanogen does it - empty address book, camera that always takes black pictures, etc. But I didn't think that Google would ever do that, and @T-A's link to howtogeek.com seems to confirm this. The app will fail on api calls that previously worked and you'll be stuck restoring the permissions.