A Nintendo spokesperson informed Japanese website IT Media this wasn’t an announcement from the company. “From the next quarter and thereafter as well, production [of the Wii U] is scheduled to continue,” according to a translation from Kotaku.
With the Nintendo NX announcement coming some time in 2016, we wouldn’t be surprised if Nikkei’s report turned out to be true. Nintendo wouldn’t outright confirm the report as it has current and potential Wii U owners to keep happy until the NX is announced. If customers knew production of its current console was going to end in the near future, they’d most likely just wait until the Nintendo NX was released.