I really doubt it.
Nintendo is in a critical situation right now, having massively failed with their latest home console and with their handheld business getting smaller because of the mobile games, they really need the Switch to be a clear success. Because of that, they can't afford to piss off their current consumers and the bad press they'd get with such cancellation.
No, they won't cancel the Wii U version.
Please excuse my bad English.
Currently gaming on a PC with an i5-4670k@stock (for now), 16Gb RAM 1600 MHz and a GTX 1070
Steam / Live / NNID : jonxiquet Add me if you want, but I'm a single player gamer.