Given that breaking update regarding the discontinuation of the Wii U: I would have to imagine that the NX would indeed be released later this very year, more or less coinciding with the Wii U's discontinuation to have something out there in the market. The traditional Thanksgiving timing seems especially likely, to tap into the hot Christmas holiday season for sales.
I think they are thinking of the Christmas sales and don't want Wii U to get in the way of the Nintendo NX sales. It didn't make sense keeping the Wii U on the market when they were clearly aiming all their resources at the NX. Everything points to the NX being a huge success so it's more then natural they would have to put the Wii U to the side.