Forza 7, crackdown 3, state of decay 2, sea of thieves, Ori 2, and cuphead are the xbox exclusives (that also all will play on PC). only cuphead and forza come out this year though, and i think forza and Ori were the only ones people didn't know about.
There isn't a single game coming out AT xbox one X launch that is exclusively available on it, so kinda weird yeah. I guess you could get a better version of Forza, Assassins Creed Origins, and maybe some other stuff (South Park?) if you run it on xbox one