It still had a Q4 2016 release window on Wii U as of two days ago and, as far as I can tell, there wasn't any word from the developer that they might forgo putting it on Wii U in favor of Switch until yesterday. The Switch reveal was also well over a month ago at this point. Even if this looked like the likely outcome to some of us, I can understand why some people feel blindsided when it was this close to its stated release date.