I would say Li Long, Rock, Hwang, Aeon, Yun-seong, and Setsuka should all have prevalence over Algol, at least with regards to SoulCalibur VI.
SoulCalibur VII will thrust history forward to at least 1591, which is where Algol rises (or at least, where he rose originally, assuming Zasalamel or Cassandra don't cause history to change), and so having him come out then makes a lot more sense. Dampierre is more a toss-up, as his placement is just... random, and they haven't truly established his role as anything above a joke character, since he got nothing in SoulCalibur V, all we really have to go by is his questionably-canon appearance in Broken Destiny, and, well... yeah. Maybe Unbreakable Soul too, but no one played that, so that's a mystery.
But all that aside, Hwang and Aeon really should have been in the base game to begin with, and there are more than enough clues to suggest that was the original plan.