Yeah, I don't think they're interested in Luke as a character either. But since Kai, Jo and Liv/Luke are all connected to this Gemini coven/the mystery of 90s hell and we're going to get flashbacks about that, I could see being that the main SL for the season.
And it could also turn out that the coven is behind the Tripp/vampire killer SL too. I mean, since everything is connected on this show, you never know.