This is a pretty serious loss, as pretty much any current surround headset available for consoles today runs on the optical connector and requires a Dolby Digital 5.1 signal. These headphones will be limited to stereo with Xbone (but 5.1 is supported on PS4):
Or take my peculiar AV setup: I like to play games and watch movies with an Astro surround-sound headset, which decodes Dolby 5.1 audio from an optical input cable. However, the Xbox One is currently only able to output stereo and DTS Digital through its optical output. My headphone receiver can't read DTS Digital, so I have to output in stereo, and my surround headphones turn into regular old headphones. I've been asking Microsoft for the last week if they intend to add Dolby output to the optical audio port in the near future (it's an option for HDMI output), but haven't gotten a solid answer on whether a fix is coming.