Let me put it this way. I wouldn't ever discount the idea of 10 fighters after Season 1 is over.
My thing is, just, that we don't even have Challenger Pack 5, and we're talking about picks 6-15? Bruh, that's a way to burn out conversation...which'll make this place deader than a doorknob.
Are the possibilities endless? Well, maybe. We could get a 1st party pick #6, which would definitely shift the conversation. Or, Pick #6 is yet another 3rd party.
I think it's easier to break down the conversation based on the pass, as it's an indication for what's to come. For all we know, at TGA Doug Bowser shows up and says, "We're adding some characters Nintendo fans know and love, as well as some gaming icons!" which tells us a bit more. Or it's just, "Keeping up with the same model".
I mean hey, speculate to your hearts content. But once your expectations get to a certain point, it's hard to dial them back. I was the same way when I assumed that Snake was totally coming back after Cloud was revealed. I just knew they would do it.
They didn't.
Just enjoy the ride, enjoy the TGA event, and crap yourself when the next character gets revealed.