I really loved Mario + Rabbids and would like to see a sequel. I would not want to see Zelda + Rabbids though.
There is a reason why Mario + Rabbids works. Both franchises are whimsical. The Mushroom Kingdom is a whimsical dream-like place. The Mario franchise has always been whimsical, but they aren't mischievous. The Rabbids are both whimsical and mischievous. So the Rabbids are the comedy and the Mario people are the "straight man" types, but it all fits, because it's all whimsical to begin with.
So there are other franchises, like Kirby or Donkey Kong or Splatoon, that would work just fine with Rabbids. Even Animal Crossing would work fine with Rabbids. Then there are other franchises like Metroid or Fire Emblem or Bayonetta, that wouldn't really work as well. I would put Zelda in this category. I know there are cartoonier Zelda games, but there are reasons why people complain when they make those. Most Zelda fans want Link to be a badass in a dangerous world instead of in a zany cartoon. I personally wouldn't want a Zelda + Rabbids crossover.