I believe they are done using some kind of capture device that is grabbing the stream via the HDMI output, and I've not seen any with HDR meta data as the source has not been hacked yet.
I'm interested in getting one of the XBOX One S's as a 4k player, seems like the most cost effective way to do it, and also provides the console experience should I so wish to use it.
Sadly my AV Receiver does not seem to support HDCP so I'd probably either have to run it directly to my TV (it does support HDCP) and then rely on ARC for the audio, or run two HDMI leads out of the XBOX One S, one to the AVR and another to the TV. Potential 3rd option I guess would be a splitter or similar. I'd probably upgrade the AVR in the future but it was something I wanted to put off doing at the moment.
I'd be very selective about which films I cared to watch in 4k though, the BR's are expensive compared to their 1080p counterparts, would probably stick to a best of the best scenario, or films I think I may re-watch occasionally.