Since I don't know anything about technical mumbo jumbo I'm curious about an Ice Climbers thing. We all know the 3DS couldn't handle them, but let's say that Sakurai ignored the roster parity thing and put them in the Wii U version, would they still work in 8-Player Smash? I imagine 16 Popos and Nanas would be sluggish as hell.
Considering they had to remove stage elements to make some stages work in 8 player smash my guess is no.