I'd say Rachel and Momiji have a good chance of coming back. They both have movesets Team Ninja can build upon, Rachel's boobs are enormous, both characters were apparently highly requested for DOA, and they pad out the roster.
The only ones with guest status are the guest fighters. I understand there are players who like the VF fighters but I wouldn't be upset if they were removed for 6.
Just a thought I had, I'd hate to see any characters (outside of the VF ones) removed from later games. Although, I wouldn't be adverse to TN adding a few more guys next time haha
The only guest stars in the game are the VF characters that very likely will not be included in DoA6; Momiji and Rachel come from NG but you can be sure that they are considered proper characters of the roster. The only TN's character with a chance to be removed in the next game is Alpha-152.
Of course everything putting aside problems as limits of resources and time (but hopefully, considering the success of the Doa5 series this shouldn't happen again as for DoA5 Vanilla). However, even in a such eventuality be sure that the priority for a character to be cut would be on the males.
It would be highly unlikely that new characters would be excluded in DOA6. It's even highly unlikely that Rachel and Momiji would be excluded as well. P4, Marie, and Nyo have provided positive reception to TN as new characters, so due to their popularity, we're definitely going to see more of them.
The VF fighters are guests from other series. New characters and guest characters have different meanings. P4, Marie, and Nyo are new characters (with P4 being a clone and Nyo being a successor of Tengu). Rachel and Momiji are guests, but NG and DOA are of the same universe, so they probably will get the Ryu treatment and be promoted to series regulars.
I know new and guests have different meanings, but devs make odd choices at times **glares at SC5** so you'd understand my concerns. I imagine it's the same feeling as people hoping for Hugo/Poison in SF5 or Skarlet in MKX. But like I said, here's hoping we don't lose anyone at all
I don't think DOA would exclude any of the female [new] characters (since Rio WAS a guest as well). xD
I mean, Lisa didn't seem like a martial artist in Xtreme, but she turned out to be in 4 (which I assume was not the intention but Itagaki had to write her in to be one).
Nyo and Marie are original characters made specifically for DOA they're safe. Rachel and Momiji are here to stay as well as they were never promoted as guests only as dos characters. And finally Phase 4, Leon and Ein will probably be back as unlockables in 6 the only characters at risk are Gen Fu, Alpha and the VFs
Why do you say Phase-4 as unlockable? If you put her in the same league of Leon and Ein because not getting a role in the story mode, you can be sure that she will be a key character of the plot of DoA5. (By the way I believe that Leon and maybe even Ein will get a role in the DoA6' story too).