Nintendo really doesn't want you buying the digital version of Donkey Kong Country: Tropical Freeze anymore. With the port hitting Switch this week, the digital option for the Wii U version has been removed from the Nintendo.com listing. All that it shows now is a physical option. We're not sure if the actual listing has been yanked from the Wii U eShop itself, but Nintendo is definitely going out of their way to try and hide it if it's still there!
UPDATE - It seems the game has been removed from the Wii U eShop altogether.