It would be great if devs could just add a flag for ps4 games on ps5, like ps4 pro games.
To enable a higher res or frame rate on ps5, with not that much work from devs.
It's safe to assume that most console developers, especially lazy Japanese ones, are tying game logic to refresh rate, so stuff like 120hz is probably out the window for most games. This is all an unfortunate side effect of developers who've always worked on fix platforms and never had to handle real software architectures like PC developers who had to make software that was actually robust.