Re: Certificates
You're missing the point.
The certificate wouldn't say Microsoft, but unless all app submissions were checked by hand to ensure there were no mentions to any other application or software not released by the same developer it wouldn't be caught anyway. The certificate would match the developer (in this case Extension-) which would pass the automated checks.
As it happens all apps submitted to the Play store must be signed anyway, but only with a auto-generated certificate from Android Studio (as far as I am aware) which clearly doesn't help.