Requiring Apple to revoke the app's certs would disable it on Apple devices.
Doing similar on the Android Play Store would ban the app's execution on Android devices (called "dropping the ban hammer" at Google.)
IMO, banning downloads means little/nothing. It's just telling the idiot millenials to hurry up and download it and gives them three days to do so.
What I like about this move besides being BOLD, is that it will bring AWARENESS to todays youth whom survives on this app. daily, hourly. They will be forced to ask questions, initially they will be p*ssed, say What the F’, yet will have to in some way have to question why? For their own good and future, it brings to the forefront that China is not out for their best interest.