In the light of terrible morning Switch event no one in their mind would buy that overpriced piece of plastic on the launch. 

My thoughts that Wii U version of Zelda have a solid chances to sell better.

Even the Wii U sold well at launch, no way the Switch can't also. I think a lot of people myself included will cave and get the better version if they weren't going to already. Plus, Wii U is dead, while Switch is just beginning, so the Switch version will have much longer legs.

I think the Switch will.

I would guess that at launch the Wii U version sells better, but in the long run the Switch version will outsell it. Of course, that depends on how successful the Switch turns out to be. It's possible that with a good enough launch the Switch version can sell more immediately as well.

Switch will easily. Like 4:1 at least.

The one that people bought more.