Super Smash Bros. Ultimate has now been updated with version 1.2.0. See the full patch notes below:
Online Gameplay
– When matchmaking in Quickplay, the Format setting of your Preferred Rules will be more highly prioritized. This may cause matchmaking to take more time, and there’s still no guarantee that you’ll find a match that has your exact Preferred Rules.
– Increased the stability of the synchronous connection within Battle Arenas.Misc.
– Game balance adjustments.
– Various gameplay fixes.
– The fighters that had specific adjustments are listed below.Adjusted Fighters
Donkey Kong, Link, Kirby, Luigi, Ice Climbers, Young Link, Olimar, Toon Link, Villager, Greninja, Pac-Man, Duck Hunt, and Isabelle
Source: Super Smash Bros. Ultimate in-game notice