These ideas/assumptions of the roster break down have probably been brought up before, so I apologize beforehand.
I'm assuming Gematsu is correct, with Chrom, Shulk and Chorus Men added, and




cut. I am also under the impression that Mii Fighter replaces the random button or works out some other way that doesn’t take up a slot on the roster.
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Five Reps (15)
Mario, Legend of Zelda, Pokémon
Three Reps (9)
Kirby, Star Fox, Fire Emblem
Two Reps (6)
DK, Metroid, Kid Icarus
Singles (14)
EarthBound, F-Zero, Yoshi, Wario, Ice Climbers, G&W, Pikmin, Animal Crossing, Wii Fit, Punch Out!!, R.O.B, X, Rhythm Heaven, Golden Sun (or another series)
Third Party (3)
Sonic, Mega Man, Pac-Man
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Some more assumptions:
Pokemon’s 5th rep could go either way, but I think

could be replaced by

, despite Jiggly being an OG 12.
Now, if there are in fact 50 characters, I believe the three series in the Two Reps category will go into the Three Reps, adding Ridley, King K Rool/Dixie Kong and Hades/Medusa. If this is the case, I think our next confirmed veteran could be

, leaving every series (aside from Mario and the Singles) with one unannounced character.
The starting roster could be 30, with 17(20) unlockables. Excluding Miis, there are currently 32 characters confirmed. If

&

are announced next, the starting roster would be all announced characters minus Luigi, Sonic, Mega Man, and Pac-Man.
This means

&

would now be unlockables, despite starting in Brawl. I am under the impression that the current lack of villains/rivals confirmed so far has to do with the common idea of a villains trailer or something other. Since Bowser is already a starter, Mario’s rival would be Wario, just representing his own series.
I don’t have an idea of how the DLC characters could work (maybe the same way Mii Fighter works). I could also be completely wrong about everything, but I felt like sharing some thoughts as a first time poster.