Hey guys. What if the character ends up being Spring Man, but..... not Spring Man?
Fast forward to 31:20. Kosuke Yabuki is talking about the ARMS comic at a GDC panel on the ARMS game from 2018. Here he drops that the Spring Man we see in ARMS is the third dude to have carried that title. There were two other 'Spring Mans' before him.
Now this comic hasn't seen the light of day since. Its release got delayed and now we don't know what's going on with it. The lore may be changing behind the scenes. There's also the question of whether the Party Crash Bash tournament will have any influence with the series moving forward, or if it was just a fun event.
For reference, Splatoon 1 had a Splatfest with Callie and Marie facing off. It's arguable that the loser of this event became the villain in Splatoon 2's single player campaign, and the hero's ally was the winner of the event. We don't know this though. I don't think this was ever confirmed, but is speculated.
For ARMS, I've speculated in the Min Min thread, that since Min Min won, she might carry Max Brass's title of champion in a theoretical ARMS 2. But who knows, maybe it might have influenced the character pick for Smash, or meant nothing at all. Guess we'll learn in time.