I honestly think we won't see many FSR2.0 games, most devs will continue to use either Unreal Engine's TSR or TAAU... or their own engine's up-sampling which are usually either on par with FSR2.0 or better.
interestingly Ghostwire Tokyo didn't use TSR on PS5 even tho it has TSR implementation on PC...
so render time could also be a factor. it could be that it simply is too taxing to use and devs will opt to just use a simple upscaler like Ghostwire Tokyo did on PS5
that would be a shame if the tech improves and is genuinely a good option. You don't think we will see it now it's a apart of Xbox XDK? or GDK or whatever the latest one is called lol