Yooka-Laylee will not be released on the Wii U as originally planned. Playtronics announced that they will instead develop the game for the upcoming Nintendo Switch. Development plans for the other platforms remains unchanged.

The development team outlines their plans in this new FAQ.
Why have you transferred development from Wii U?

The team did say that those who backed the Wii U version will be able to change to another platform at a later date.