I feel like there's not too much NoA could have said. "This game doesn't meet our quality standards, so we're looking for a different publisher."
You can see how that would send a poor message and potentially hurt their ability to shop the game to other publishers...
There could have been better PR than that.
Instead of saying absolutely nothing, ignoring the game entirely at E3, and then issuing a hasty tweet only after all rumors were leaked NoA could have issued a statement (preferably before E3) that they felt the game didn't mesh with their primary demographic in North America so were looking for a third party to share publishing duties with. Or just that they were hoping to have an announcement regarding the game at such-and-such date with everything else left out until details were agreed upon.
Ignore the "quality issue", which is a bogus statement anyway based on Wii games that weren't released due to quality concerns.
Ignore low sales potential due to the fact that Wii U install base and software sell-through rates for anything non-Mario are pitiful.
Focus on giving fans
something, instead of leaving them to assume the worst. Focus on living up to your goal of controlling the message instead of letting others dictate how your are viewed.
But hey, I'm quite obviously not a PR guy. My opinion is worth jack all in this matter - and my growing frustration with NoA means very little to anyone except myself and the friends/family who I introduce games to.