According to ShortFuse on Reddit Smash Wii U sends an init command to the GC adapter upon startup and you can go into Wii Mode after and use it as a HID device. He says Devolution as an example so anyone want to try it with Nintendont?
http://www.reddit.com/r/smashbros/comments/2n34sg/just_to_confirm_the_gc_controller_adapter_does/
If it works it means we would just have to load Smash Wii U first until they add it in the homebrew app itself.
http://www.reddit.com/r/smashbros/comments/2n34sg/just_to_confirm_the_gc_controller_adapter_does/
If it works it means we would just have to load Smash Wii U first until they add it in the homebrew app itself.