They asked if UE4 would run on Wii-U and they started laughing. That should be all the answer you need. Does Wii-U support all the features needed to run the engine? Probably. Does it have enough power to do anything usefull with it? No. The Wii-U's gpu is about on par with the integrated graphics you get for free with a $60-$70 Amd cpu, and is very low-end in the PC graphics market.
It wouldn't make much sense either, the engine is designed for more powerfull hardware and wouldn't do the Wii-U justice anyway. Any engine designed by Nintendo themselves will get way more out of the system.













