Does anyone want to place a bet with me that Raidou is not confirmed or coming? I'll bet the first costume pack. Because "basically" doesn't confirm anything.
When Shimbori said "I pick because of story." Something
@Onryoki brings up a lot. It's not actually an answer more than it is an easy way out, because Momo and Rachel could easily be infused into the story, especially with how some of these other bonus dlc characters from DOA5 have been plugged in.
If Marie Rose can be Helena's servant, Momo could easily just be Ryu's... And with Rachel's fiend hunting history, she could be either tested on or help slay a boss in the story.