If your running All Boards, then yes you have to win.

That's so sad :(

To this day, I'm still surprised how that's not a category for this game. It was in Smash 4 but not in Ultimate. If this ever becomes a category, it will be the only thing I'll run in this game XD. Please 1v1 Iron Man a category please:) But the question is, do you need to have everybody in Elite Smash?