stg83: Well Windows 10 is going to be free for everyone using Windows 7 and upwards so we can't really complain about it only being playable on the latest version. Apart from that all these games will be using DX12 which is also only available on Win 10.
Not really interested in Killer Instinct, but really glad to see Gears of War Ultimate edition coming to PC as its the only Xbox exclusive I have ever been interested in having played the original on PC before.
It certainly doesn't use Direct X 12 on the Xbone, so that's hardly a legitimate reason for making it Win10 exclusive. As OP said, they're just trying to bribe people into making the transition to Windows 10, same thing they've done each time they released a new version of their OS.
On topic, Killer Instinct 1 & 2 were fun back in the day, but I don't care much for the new one. More interested in that YookaLaylee game, or whatever its called, by the former Rare Soft members.