That is very risky unless you are very good at disguising yourself on the internet away from the reach of Nintendo. I was wondering to myself about this last week, and decided to pull my Stick Magician demo from that ISO site due to morals™ and wanting to build up a good reputation for myself when I decide to actually partner up with the big gaming giants and go into proper commercial game developing!
By all means do it, however your game will practically still be in the hands of Nintendo because you are distributing compiled and copyrighted code made from both the Unity Wii U exporter, and the Wii U SDK, which technically belong to Nintendo and are propietary pieces of software, and you may find yourself being in a bit of legal bother. Unfortunate, but true.
However, Nintendo never seem to take any action anyway, so... still go for it, I guess?