The problem is that you'll permanently handicap the game by accounting for last-gen. As a major example, you wouldn't be able to capitalize on the improved load times for online play provided by the SSDs in the new systems, or truly take advantage of the superior CPUs.
Huh? If you're playing PS5 against PS5 players it would most assuredly take advantage of the faster loading, like that's a given and has been a thing. If you match with PS4 then yeah you wait a little longer, nbd, you could probably choose your player pool anyway. This happens with SFV on PC.
I think you need to look at high-end PC gaming in general, and the enhancements offered by X and Pro, and then remember we're also dealing with fighting games. Power is not a valid concern, an incredible looking MvC4 is very possible on today's hardware and can certainly take advantage of next-gen capabilities at the same time.