Not sure how this is going to work with the stated functionality of the XBone. With PIP/Window views and instant swap to your media, there is NO WAY they’re just going to leave HDCP out of it. They can’t with the media direction they’re taking.
The devil seems to be in the details of the “which stream that doesn’t support HDCP encryption”. Does it disable media and other functionality when using it? So you have to play with setting everytime you want to record and set it to game only? Does it just cut the feed?
Either way, a non issue all around. $25 worth of stuff and you can get around any HDCP for recording and not have to worry about those things above at all. Plus, as you said it's a minority problem.