I just tried this on Xbox as well which just got native mouse and keyboard support (game devs still need to support it in their game) and I was able to use WASD to move as well.
I plugged in a mouse but sadly it didn't operate the camera, I also noticed that if you hold enter on the keyboard on the pre-lobby screen the game switches to keyboard controls in the UI.
Shame we cant set keyboard controls up or they could just add M&K support via an update one day.