yeah any first party game - developed by Microsoft, which stuff like Forza, Halo, Gears, etc are - are always on gamepass forever. JUST the base game though, you have to pay extra for DLCs, expansions, etc. Usually, some games include them free but not the forza series.
i think earlier in the thread we talked about tricks to getting gamepass, but the basic gist is if you've never subbed you wanna build up 2-3 years of games with gold or basic gamepass (cheaper), then convert one time to gamepass ultimate. It converts at 1:1, so if you have 3 years of Gold you'll get 3 years of gamepass ultimate. There were all kinds of crazy ways to build up gold even too, like rockstar energy drinks giving you 6 weeks for 2 cans or Taco bell fucking gives you 2 months for $5 but I dunno if there are any deals now.
There will probably be a bunch more crazy ways closer to Halo Infinite release.
I've had 3 years of gamepass forever and i bought enough gold codes long ago to keep myself rolling forward for like another 5 years. Its an insane value, considering this month alone I've played Hades, 12 Minutes, and Psychonauts 2 all with gamepass. Way, way, way better than PS+