Not at all. While a nice evolution for an overlooked mon its not even up there as one of the more popular mons to come from Galar and Gen VIII didn't really need a smash rep either. Pokémon had enough reps in Smash anyway.
You say that, yet getting a Cinderace, Inteleon or even Zacian with the DLC expansion would have been epic, in my opinion. Not that I'm sour with what I got, I just think it's a nice "what could have been" thing.
No, not at all. Smash reps should be the most recognizable and iconic characters from their series. While I like Sirfetch'd well enough, it's mostly just a 'dex filler and not even remotely notable enough to get into Smash. I could see it maybe getting into something like a Pokkén 2, if they were to ever make one (I don't think they will) but that would be about it.
Truthfully I would very much appreciate a Pokken 2, would give a lot more mons that have no chance for Smash a chance to shine as playable characters in a fighter without setting off Smash's easily infuriated fanbase with oversaturating one series. The first Pokken was pretty fun, and while I dont know if a 2nd is even remotely in the cards, it would be nice to see.