90 should be enough for copy paste port/remaster. Everything above will be untasty joke. But it's nintendo so i can easily expect 10 from edge.
Well fact is that Smash Ultimate is not copy paste port/remaster. Even if they used Smash Bros 4 like base for Smash Ultimate, Ultimate has so many differences, improvements and much more content in any case compared to Smash Bros 4.
Smash Bros 4 had 92 score, so this game will hardly will have lower score than that in any case.