It's probably a miracle that no one is getting deconfirmed today. In my place at least. Pretty much everyone is sweating bullets after yesterday's events. Back then, once people get a leak, it'll be tons of advanced celebration. Now, it's more like the countdown to getting your hopes crushed coz honestly, the higher-ups are starting to get really off-putting to say the least.
My guts say that we're getting another fighting game character to "bring balance to the Fighters Pass", as we already have 2 JRPGs, a platformer, and a fighting game rep. I don't usually make theories like this but it's something I'd feel like sharing, if everyone is okay with it.
We're just a matter of time before the Game Awards. Assuming we do get a reveal, I honestly don't think it'll be a "niche character". You're broadcasting your biggest announcement to kick-start Season 2 and you show us said niche character, then everyone's probably rolling eyes. If the Pass will end with a niche character, they probably want to reveal it in a Smash Bros Direct some time before the Game Awards.
I just wish that after all of this, everyone would be at least impressed and welcome the characters with open arms. If anything, it's gonna truly be a great December for the community.