@Camel with 2 thumbs I see one or two people tops requesting Gen-Fu on news updates about DOA6 and NO ONE requesting/demanding Ein. I get that they've got some competitive presence but NOOOOOOO ONE seems to be speaking up at all about wanting them in. So it's not "That" unpopular of an opinion lmao
As an Ein main I am objecting to your statement about dropping a legacy character like him for unexplained reasons. To be completely honest though, they might and will probably appear in the game as dlc characters later on. Momiji and Rachel playing a role in DOA6's story would be nice, since every character post Ultimate in DOA5 didn't have a canon story or canon appearance in the game iirc.
Ein and Gen Fu are on life support since DoA3 anyway… their movesets have barely evolved since then. Leon received more changes from DoA4 to 5 then those 2 combined.
To explain this unpopular opinion of mine isn't to remove Gen-Fu or Ein from the game period, but to relegate them to bonus character status (Free DLC like Tekken is doing with their veterans), and in the core roster make Momiji and Rachel actual DOA characters if there's no intention of resurrecting Ninja Gaiden since they carry more popularity and presence.
You can still add characters while canonically no longer existing. Most of the costs regarding such characters is how profitable the returns will be for such characters.
By logic, Bankotsubo would be considered a legacy character but he was replaced entirely. If it came down to it, Ein and Gen Fu (even Leon unfortunately) have a chance to receive that treatment.
But at the same time, that's not always a good look because it's just a way to scapegoat for TN's way to draw in it's base consumers just to please a crowd by gender-bending slapping "girl" on a character due to unpopularity as a male, which can be bad on TN's end because it makes it tough to take them serious no matter how much sales increase.