If it were me, I would pay off as many of the original Rare guys as I could and have them make a direct 2D sequel to the original SNES game using the same graphics.
Or just make it in 3D.
Killer Instinct was a 2D game, but it used 3D pre-rendered sprites due to hardware limitations. (Minus some Mode 7 sequences that looked impressive in the day.)
It tried to be 3D without actually being 3D, which is simply not needed anymore.
Very true, but I think, marketing wise, a return to the SNES style would hit a lot of people in the nostalgias if it was done well. That's partly why I suggested doing it. Also, I personally just like 2D fighters more... so there's that haha.