You are not gonna get into any trouble for doing it and you certainly don't need permission from anyone on this board.

Not legal in any case. Even if you own a copy of the game (for Switch or WiiU) you are not allowed to play it on PC but only on the platforms it has been released on. If Nintendo wanted Botw on pc, would have released on it, instead Nintendo didn't do that. If you own a copy of Bioshock Infinite for PS3 you can't play it for free on PC or 360. Nintendo release it on WiiU and Switch to sell their console, so if you wanna play it you have to buy a Switch or WiiU, that's all. Any other case isn't legal.

The legalities depend on what country you are in.

In general... Emulation itself is perfectly legal.
And if you own a WiiU copy and drop it into your PC's disc drive and run it that way, that is also legal in most western nations.

Some countries like my own legally allow you to make duplicates of the media you already own.

Now where things get tricky is if you own a Switch copy of the game... Sadly you cannot drop that into your Disk Drive and go from there due to the lack of a Switch-cart port on PC.
Now if you were to torrent the game... Then you are also uploading chunks of the game, spreading the piracy of that particular copy, which is illegal.

From a practical perspective:

Nintendo probably don't really care as long as you have bought a copy of the game. They have plenty of people who download without paying for it at all to go after.

From a legal perspective:

You have bought a piece of plastic and a license (obviously you don't own the copyright). The license is that massive document that you "agree to" when you play the game. It defines exactly what you can do, and almost certainly will not allow running on non-certified hardware.

Making a copy of the game (e.g. loading it into your PC's RAM, or displaying pictures of it on the screen), is therefore not covered by the license that you have bought, and so technically copyright infringement.

Yeah. Nah. That also depends on the country you reside in.

In most countries the License Agreement/EULA/ToS and so on... Does not and can not override your consumer rights.

For instance if someone were to take a video game publisher to court over licensing here in Australia... There is a very high chance that the consumer would win, as when you go to Purchase a game like on say... Steam, it says "Buy Now" rather than "License now" or "Rent Now". - You own that copy of the game, not just the license as that is how it is advertised as.
We have a massive amount of protections for the consumer here which allows us to legally make reproductions of any and all media for personal use.

I don't believe that's actually true. The act of downloading copyrighted material is in a grey area at best. You can't be sentenced for downloading some bits. The actual illegal thing is sharing copyrighted material. When you see companies going after illegal downloads it is because they used torrent for it. And with torrent every download is basically also an upload. Much like it is not illegal watching a movie on a streaming site but hosting that site is.

So to answer OP's question: Playing BOTW on PC is absolutely not illegal. It's all about the acquisition.

Even if you don't own the console or the game, chances are you do not lose the developer any money because you wouldn't have paid for it anyway. That's the fallacy the many opponents of piracy fall into.

If you own the Wii U version used to do so... yes.

Since thats the vesion your playing.... owning a switch version, but playing the wii u version, probably isnt legal.

Some would argue its a grey zone type of thing, since you already gave nintendo money for the game, but yeah not legal.

Best case : use your own copy of the game (wii u version), to do a dump, and play that via emulation (cemu).

I say go ahead and do it, if you want. You already paid nintendo money for the game. Theres morally nothing wrong with it.

Legal? Probably not.

Would anything happen to you? Definitely not.

Summary of thread:

If you don't like piracy - no
If you are overly partial toward Nintendo - no
Everyone not in the two camps above - yes

That's not totally right.. becourse you have to own the hardware to play it on also.. even if you not use that hardeware..

It's not legal to go to gamestop and buy a used copy (or new for that matter) of a ps1.. wii.. whatever console game.. and then go home and rip it.. and then play in an emulator.. if you only own a pc..

But if you have a old ps2.. and have a backup.. and your ps2 then dies.. its legal to play on other hardware.. becourse you have right to play that game.. but its not legal if you never have had the hardware that can play it..