MK 8 was hit on Wii U despite the low userbase (uninteresting console, too!).
If there's a Wii U game that can sell really well on Switch - and the console itself, btw - it's MK 8.
The game's sales were cut due to low install base, so, no wonder we are seeing this game selling really well worldwide.
I don't see it surpassing Zelda BoTW, but it might end up getting close to it.