Version 1.2.0 You can confirm your current version by checking the upper-right corner of the title screen.
Offline Gameplay -Adjusted difficulty of approaching challengers.
Online Gameplay -When matchmaking in Quickplay, the Format setting of your Preferred Rules will be prioritized more. This may cause matchmaking to take more time. Also, there is no guarantee that matchmaking will be done exactly as shown in the set Preferred Rules. -Increased the stability of the synchronous connection within Battle Arenas. NOTE: Online features require a Nintendo Switch Online membership.
Misc. -Game balance adjustments. -Various gameplay fixes. -The fighters that had specific adjustments and changes are the below: --Link, Donkey Kong, Kirby, Luigi, Ice Climbers, Young Link, Olimar, Toon Link, Villager, Greninja, PAC-MAN, Duck Hunt, and Isabelle
People are probably gonna complain about challengers being nerfed (assuming that's what it was).