wii u version looks really good and this was old footage so the final version will look better.

There is that difference that people have been questioning about!

draw distance being majorly difference in terms of depth/detail is kind of a pretty relevant thing for an open world game

Now we know why it looked washed...

The Switch version is less foggier/washed and the colors pop out more. Honestly though, the Wii U version is just fine, the difference isn't night and day.

I just hope the Wii U version doesn't run like an N64 Zelda game (19-21 fps)

You won't miss much if you calibrate your display correctly. It goes wrong when you capture a video intended for tv display and then show it on a pc display without converting to full RGB. Which is why it looks washed out on you tube. I've tried to spot the difference between limited and full RGB, both calibrated correctly on my projector (it has a build in waveform analyzer to perfectly calibrate contrast) and no matter what game I try, I can't see a difference.

It would be nice if WiiU had the option. Perhaps with the newer 10 bit displays and wider color gamut, full RGB range might actually make a small difference. But the colors looking washed out or generally foggier in the comparison is just a matter of incorrectly capturing/displaying the footage. It has nothing to do with the game.

What decides it for me is whether or not we'll get Japanese voice-acting on the Switch version. If no voice-acting, then I am going to get the Wii U version so that I can play undubbed (via homebrew.) NoA needs to stop being cheap and hire proper voice-actors.

True, but is it worth $300 :)
I managed to live through 80 hours of Skyrim on ps3 after all.

Yet I did buy a ps4 pro for psvr improvements. If Switch had Zelda in VR, day 1!

Wow looks much better on Switch