I’m confused. What’s the violation here? Apps are supposed to open links in Safari “outside of the app” unless they have permission? What about in-app browsers

I’m confused. What’s the violation here? Apps are supposed to open links in Safari “outside of the app” unless they have permission? What about in-app browsers???? Twitter, Facebook, Instagram... they all open links inside their app, in an in-app browser. Can somebody please clarify Apple’s rules here? (No snark please.)