Remember as well, S.T.A.L.K.E.R. has never been on Console before. This is a smaller dev. In all likelihood, if it came out on one platform that is not PC, it probably would have been PS5 as Sony got many defacto Indie console exclusives last gen due to adoption rate. MS is helping in the promotion of the game and is not taking it away from the core audience for the game. They are adding here, not subtracting.
Same goes for Nintendo with Among Us.
Timed Exclusivity is not something I love, but lets be real, there is a substantial difference between STALKER 2 and Final Fantasy XVI.