Worse than this, and to the point of this post - you can’t offer comms service in China unless it has a way to be snooped by government. So some comm services like Skype have to offer a separate app, just for China, which affects all messages sent and received by users of this version of the app, even if it comes from a regular app.

I was telling my friends who moved from China and kept their iPhones, to just buy a new one... just in case...