We always get cuts anyway, it seems, until DLC and/or an Ultimate edition rolls along, so I guess speculating on who will be cut in 6 is something to do.
Even tho Christie sucks and she isn't popular from what I can tell, along with Lisa, I think those two probably have roles in the story, so they'll still be in to begin with. Excluding the VF/guest characters, people like Rachel and Momiji could be likely to go, since they don't have much story position at all, but I think Momiji has her fans so she'll stay. It's Mila I worry for. She doesn't deserve to be cut.
The most likely ones to not make it (at least at the start) I think are Leon, Ein, Alpha, Phase (tho I expect a clone to return, but prefer not), Rachel, Raidou, Eliot, Mila.
Possible ones to not make it, but most likely will I think are Gen Fu, Lisa, Christie, Brad.
I think they could make it about a 25 starting roster. DOA5 vanilla started with 24, and rose to 36 by the time of Last Round.