MK and Smash take lots a resources and time from Nintendo, so I would love to see what will they made instead new MK and Smash games.
The problem is they shouldn't HAVE to choose. People love brining up how much stacks of cash Nintendo have in the bank, yet that's not a good thing. They shouldn't have had software droughts with the WiiU, they should have spent money and created more studios, but they just put it away in some vault and do nothing with it.
If they want to make more games, spend the vast amounts of money they have to hire more staff.
But yeah ignoring that it will be interesting to see what games Nintendo come up with if they choose to not develop new MK/Smash experiences for the Switch.
Predictions (Made July 2019)
LTD: PS4 - 130m, Switch - 110m, XBO - 52m 2019 : PS4 - 15m, Switch - 18.8m, XBO - 4.8m 2020: Switch - 22m (Peak Year)