Well to be fair, there probably has never been as many eyes on Smash as there are currently especially when you consider the rampant advertising of both the game and the FP. I don't remember advertising for Smash 4 DLC at all apart for Nintendo Directs. It would be extremely in-opportunistic on Nintendo's part to not capitalize on this attention by deciding to end with a bang. Granted, I could certainly be wrong and Crash might not even be that bang, but he is one of the few huge characters left. He's also THE largest titular character of a franchise that has yet to be included, which furthers his chances IMHO. For example, I would suggest Resident Evil and Assassin's Creed are more recognizable to a general audience than Jill Valentine and Ezio respectively. We'll just have to see I suppose...
I wonder if maybe there could be a niche first party thrown in there at the end like Corrin, like if Nintendo wanted at least one new franchise of theirs in and it would help with the extreme costs, maybe one that couldn't make base game because of the prioritised ballot winners and new favourites that had to take up the limited slots to promote the game well, while they could throw in a more niche character at/near the end that's also a financially viable position because it's along for the ride as part of a package deal with much bigger characters, as opposed to being a standalone DLC that can only sell on its own.
Though I wouldn't blame them for going the all BIG characters route either, that's also pretty interesting and profitable. Heck, with how much promotion and hopefully resultant success the FP DLC is getting, CGI trailers and in-store DLC cards, maybe they'd be financially more open to another wave of DLC with perhaps less manpower and finance needed, though one must keep expectations reasonable.
So speaking as one not too familiar with her character, could they honestly get away with Dixie Kong being an echo of Duddy? I hear their abilities are too different to do it justice, but if she was Ken levels of unique could it work? I don't know if that's what Sakurai would have wanted when originally envisioning her and Diddy as a tag team in Brawl, but maybe she could have that gun she uses in Returns instead of Diddy's, helicopter hair for up special, throws where she uses her hair to have grabbed the opponent and some attacks using her hair?
EDIT: Whoops, that was a bit of a general question for the Crash thread so Ima post it over there.