Would you like to see a Nintendo character in MK11 and an MK character in SSBU?

[irstupid]

Neither.
MK is not MK without their fatalities, and so would be out of place in Smash.

I don't want to see any Nintendo character fatalatized either and I doubt many companies would want their mascots/brands being fatalatized as well, so disregard Nintendo, I don't see many companies wanting their characters in MK period.