To everyone saying it’s a port, there’s literally nothing implying it being a port of 4.
It was being developed way before the switch was even announced, supposedly while smash 4 was getting towards the end of development. If anything, it’ll use a similar engine to the Wii U version and nothing more.
The trailer also doesn’t say it’s a port either. If this were a smash 4 port, it would have been announced as one right away instead of just having the title be super smash bros.
If this were a port, the trailer would have shown smash 4 and at the end show off at least inklings and a new splatoon stage and promise other new content as well and it would be called super smash bros for Nintendo switch deluxe with new funky kong mode and knuckles or something like that.