I would buy a new Dead or Alive game absolutely, as long as it's a fighting game or if it's an Xtreme game at least put the minigames in it again. But I think Koei Tecmo are content with the franchise as it is, they give it a tiny budget to maintain the gacha and maybe make a small Xtreme game every few years. A small investment for small but consistent returns, keeping it only in the Asia market to keep it away from western journalists.
I think they should consider using the characters in more games and collaborations since that's by far the most popular thing about Dead or Alive or Team Ninja games in general. I would pay money for any game if I knew it has Momiji in it. I even try to recreate Momiji in Team Ninja's other games.