Ryse is owned by Crytek. MS tried to fund the sequel, but they wanted IP ownership and Crytek said no, so the deal fell apart.
MS just gets publishing rights for some games. They often allow the IP holder to release on PC through another publisher.
Remedy is still independent, but they have been close to MS for years. Considering the amount of money seemingly going into QB I assume the relationship is still pretty strong.
With this in mind tho... PC port down the line would still be possible. I just think most games come to PC from the xbone.. at least the ones i have been following. Even D4 came to pc. lol.
It would be pretty amazing to see this game running with a good rig. 60fps at native 1080.