Stripping encryption is one thing, sure. But for the backdoor, you'd have to have the clients phone nsaserv.spy/writeremoteconnlog then or sure, write some record on the client's device. You can't "tap" encrypted communications unless you can figure out how to factor integers then you'd get a Field's medal.

Or, ofc, get people to adopt insecure protocols. That we know (or have good suspicion) they've tried.