TBF, Microsoft have already said that games like COD and other major ABK IPs will remain multiconsole, and probably even get Nintendo ports for at least some of them. So people aren't getting cut off there. For new IP, those may or may not be Xbox/GamePass exclusive; I'm sure some will, others might be multiplat. But that isn't necessarily any different than if they just co-funded a bunch of 3P exclusives anyway, hard to say people on other platforms will be "cut off" if it's a new IP.
There's so many other shady bits going on with ABK right now that the FTC are probably more interested in; I don't give two cents about political grandstanding especially from the Democrat side. Not just for the reasons you mentioned but also considering how many of them get money from and invest money into these same tech companies, but want to pretend they're above the money. They are the money, they're right in it xD.