I'd say Zelda should be experienced only on the Switch. The Wii U version is inferior, and won't get the same updates.
The Switch will also most likely have a more robust Virtual Console.
Although Wii U I found was worth it for XCX, which is more of a legitimate Xeno____ game than XC2 on Switch will be. XC2 on Switch overall looks like they are genericizing and catering toward the "yay yay animu!" crowd, rather than people looking for a compelling RPG.
I describe myself as a little dose of toxic masculinity.