Facebook or WeChat, Apple can't ban them. Game streaming, they can. Maybe they'll change the rule in 1, 2 or 5 years if game streaming becomes so big to move enough of their customers to Android. Then they'll claim they're introducing an incredible thing. Remember copy and paste on the iPhone 3 GS? https://www.idownloadblog.com/2009/07/17/iphone-3gs-stupid-t...

The can ban them. They don't want to. They could just as easy say "we'll remove the Facebook app until you remove the gaming part". Same for WeChat.

Of course Apple doesn't want to. Both them and Apple know that without WeChat Apple won't sell any iPhone in China and without Facebook no iPhone in the western world.