The answer is DRM. In fact, almost any audio/video standard attempts have to address the elephants in the room: Disney, Warner Media, Universal Music Group, etc, and they all require DRM.
From my experience, no. The other comment mentions a standard but I have yet to see it in use anywhere.
Generally you don't see it, but then again Bluetooth became available to consumers in the late 90s, shortly before the big push to lock up all multimedia sharing.