Except Wii U is different from Wii U VC just as it would be different from a Wii emulator. The game doesn't have a Wii U version.

Also not sure if New 3DS is a category you can make. I'd definitely recommend that since the loads between 3DS and New 3DS are like night and day (and not just for this game).

New3DS isn't a possible version to make. Also you can't run the game on normal 3DS silverstar ;)

Yes, you can play the game on Wii U in two ways, but what you're describing is on Wii mode. This is provided you have a physical copy of the game. Your save can be played through both the virtual console version and the Wii U's Wii Mode. However, this means it doesn't function the same way.

If you play the game on Wii U's Wii mode, you do not get the fast loads that the Wii U VC version provides, which is why the Wii U VC version is the fastest version of the game (and is also much cheaper than buying a physical copy of the game). The Wii U VC version though is the downloaded/digital version of the game played directly on your Wii U, so you get the faster loads from Wii U, not the Wii U emulating Wii Mode and emulating the slower Wii loads for Xenoblade Chronicles.