Btw this isnt just 1 or 2 games.... or japanese styled ones.
Resident evil. Hitman, AC Valhalla, Outriders, Scarlet Nexus......
Its a patern.
The most likely reason is comments like this one:
"Got several buddies who bought an Xbox for gamepass and have 0 interested on paying a dime for a game. They consider buying games a losing proposition since Microsoft is paying for them. " - Bitmap Frogs
"Every is waiting for it to drop on GP. I won't buy any games on XBox as long as I'm paying for GP, I'll just wait for them to be free" - Cornbread78
^ there are more like these on Neogaf.
These people are likely more "hardcore" than most casuals (since their on neogaf), so you have to assume the causals are like this as well (likely to a higher degree).
If your fine paying for gamepass, and playing these basically "rented" games.
its gonna effect game sales. Even games that arnt on gamepass are being effected.
Apparently the mentality is to just wait.... eventually... hopefully it comes to GP.
The result is less game sales on xbox platforms, because of gamepass.
(which is less revenue, for game devs, and store owners that sell games on xbox platforms)