Not fussed on GT7, being able to get to a bigger userbase is probably a bit advantage considering it will have a focus in multiplayer
But GOW is the game that needs to be a showcase must buy a PS5 for this game type of deal. And one that could massively benefit from being detached from last gen limitations.
I'm the opposite.
God of War 2 I think should be fine, they've been designing it for a long time now and that team has never buckled on delivering spectacle on an unheard-of scale on any platform they target. It depends on what the history is with the cross-platform plan (technically, they never announced that it was
not cross-platform, just said, "Ragnarok is coming" and then 2021... that was back in the "We believe in generations" days, but it was also the exact same day that Spider-Man MM/H:FW/Sackboy PS4 versions were announced, so that's when next-gen exclusivity became a question for everything,) but they could have always been building a PS5 project, and at some point Sony came to them and said they need PS4 versions as well, and the response could have been, "If you can find somebody who can port
this down to PS4, godspeed to them...", and Sony did.
Porting down is tough, but it's a thing that gets done, and it doesn't necessarily compromise the original (unless the original really is is targeting the lesser model first, but that happens less than people assume, and I would bet if you talked to developers, "manpower" and "budget" and "development time" would be way bigger factors in setting the "next-gen'iness" of a project than the platform slate.) Somebody has to put in the work to get a game working on a lesser platform, or somebody has to do the work of implementing improvements of a game ported to higher platforms. You can use a game engine to make a base model that works on whatever platforms you target, but after that, each platform should be a conversation and a job, not just, "Well, we solved for Platform A, so just crank the dials on Platform Z and call it a next-gen version."
Gran Turismo 7, however, is not just cross-gen, it is probably cross-play. So if that's the case, they can't farm it out to another studio, and they can't do a lesser-version port (ala Forza Horizon) with fewer cars on the road and less physics and track objects, because it has to run the same on both platforms in an online session. They can turn RT off, they can make the cars less pretty, they can run the framerate lower (although it would have to simulate the game systems at the same rate, I believe? not sure how cross-gen games work now, I think the servers can do some compensating for a player that is in framerate hell...), but they still have to run the same general game systems on both platforms in order to play together.
Halo Infinite was in a tough spot in this way as well; if they had delivered the level of quality that the 2018 Slipspace Trailer showed then it would be fine and we wouldn't be in such a panic about cross-gen because that'd still be a nice-looking Halo (would still get tossled by Horizon IMO, but that's cross-gen compared to cross-gen, and both games would still be in the upper-echelon of games shown playable on any gen of game systems.) Unfortunately, Halo Infinite had a disasterous showing, which did call into question the idea that "scaling" was the new console generation future, but looking at it deeper, it also asked the question, How can Microsoft fix this? They can't just make an amazing Xbox Series X/S game because it still has to play online with Xbox One S players somehow. They can divide the servers and make two versions of the game to optimize both platforms, but then the user base is split and that's a problem. And they can cancel Xbox One and go "full next-gen", but would that even solve the problem when they thought what they showed was good enough at the time to go public with as an X/S showcase? All signs point to Halo Infinite having way, way, way more problems than just an Xbox One barnacle on its bow, but if cross-gen really was/is a problem, the solutions are limited.
Personally, it'd be surprising if Gran Turismo had a lot held back by cross-gen either, though. Polyphony Digital always pushes its tech, but what is it really that a GT game would do beyond just even shinier and more exacting cars?