Comment by cosmicgadget

Well they wouldn't be breaking e2ee, they'd be breaking the implicit promise of e2ee. The chats are still inaccessible to intermediaries, they'd just be stored elsewhere. Like Apple and Microsoft do.

I am not familiar with the state of app RE. But between code obfuscators and the difficulty of distinguishing between 'normal' phone home data and user chats when doing static analysis... I'd say it's not out of the question.