Is Monster Hunter Generations a port? The situation is comparable.

Something entirely different. It's like they took Smash 4, and just kept adding things to it over and over until it stopped being a simple port. It would be as if Bethesda made a port of Skyrim, but then added two new races, spears, throwing knives, ten new skill trees, 40 new skill books, altered all the daedric quests/artifacts, threw in the Morrowwind/Oblivion areas, quests, characters with Skyrim graphics, etc. etc. etc.

It's iterative. It's a heavily overhauled Smash 4, think of it as a remaster.

It's not a new game, since so much has been recycled from the WiiU version (not to mention all of the upgraded 3DS things added). It's not a straight port since so much work has been done to it. I'd still feel inclined to call it a port, but it's just barely apt for the definition.

Intentional or not, you've just very effectively described the Super Smash Bros. competitive community...

It's new. But like every Smash since Melee, they are reusing some assets. Mainly meshes. But the game has seen some substantial changes to UI, improved rendering, etc. Compare Battlefield Wii U to Battlefield Ultimate. Marked, significant improvement.

However, the gap from Switch to Wii U is not as big as Wii U to Wii. So it looks a lot more similar. I knew it was new the moment I saw Battlefield and a lot of the effects.

Comparing the previous game to this one is like comparing Street Fighter II: The World Warrior to Super Street Fighter II Turbo. On the surface, they may be the same game, but if you took away the levels and character skins, they're very different games. In SF2's case, SSF2T could have easily been Street Fighter III if the game had all new levels, overall story and endings. So when you go to play this Smash, you won't feel like you're paying $60 for a game you've played before.

How is this conversation still going. It's as new as any other smash game.
-Graphically it looks different to the Wii u game.
-new characters
-new mechanics
-new stages
-new items
-new assist trophies/pokeballs
-new character designs
-altered move sets
-most smashes have been changed drastically.
-contents from past games that wasn't in the Wii u game.
This is just what we know so far, likely there will be more character, more stages and new modes.

Graphically speaking, Smash WiiU was a 1080p 60 fps cartoony fighting game that still looks great.

Unless you want to see a ultra realistic art style there isn't much that they can change.

Go watch the latest, most advanced Pixar film.

Until Nintendo's games look like that, their cartoon games can still make a lot of progress.