The Xbox One controller has basically a USB port in it. They can transmit the DD or DTS signal over WiFi Direct easily enough and third parties will just design headsets to accept that signal through the digital port on the controller. Of course, after that the 6 channels get down mixed to stereo to feed the 2 drivers the actual headphones will have. It's a fairly pointless exercise used to market premium products to people who don't know better.
The X1 has better audio hardware than the PS4. You can have 4 controllers on the X1 doing 5.1 audio for each player. The PS4 controller only does stereo. Kinect also has its own audio hardware.
I'm highly sceptical whether this will actually be possible, could you link any source? All I've read so far in regards to this controller ports capabilities mentioned party chat only. I'd be highly surprised if game audio, let alone multiple disjunct game audio streams to multiple controllers, could be transmitted. There seems to be no mention of this controller port being "basically USB" anywhere.
5.1 headsets (like today) will, most likely, continue to use the optical audio port & a proprietary connector for the Xbone and a standard headphone connector for the PS4.