Smash Ultimate is not a port... and not a brand new game?

[VGPolyglot]

Nem said: 

• A sequel > A new game in a franchise remade from the ground up. (think Dead or Alive 6)

So, by your definition it is a new game:

https://www.usgamer.net/articles/nintendo-smash-bros-ultimate-interview-brand-new-game-than-wii-u