Wasn't this confirmed to be a misunderstanding?
"Its been confirmed that there are more options for the in-game hand, including various skin tones. Looks like there was some misunderstanding with the reps that the Business Insider author asked."
http://gonintendo.com/stories/238642-update-you-can-change-super-mario-maker-s-in-game-hand
Just makes this whole situation all the more ridiculous
EDIT:
You aren't even limited to human hands!!