I don't know about Apple, but I don't think Samsung has something in place to just ban certain "package names" from being installed. So far what countries have been doing is 1) ban the app store from distributing the apps and, sometimes, 2) try to block it at a network level.

What you're suggesting would be a escalation and we should worry about that when it happens. Package names (the real name of an app on Android) can be randomised, for example.

The problem right now is that if you own an Apple device in Brazil, you can't install the app of this VPN provider. That doesn't sit right with me. Android has its issues, but if I can find the apk, then I can install it. What can you do with an iPhone? Perhaps use a 3rd party Wireguard or OpenVPN client that hasn't been blocked yet and download a profile from Proton's website? What happens when that client is blocked too?