I don't know if Deltarune's plot will be as straightforward as "Darkners are fake and therefore sealing them away is the good ending because escapism in moderation etc" when Ralsei is a whole-ass person that's just learning how to really be friends with Kris and Susie and loves them dearly and from our perspective as the Angel looking down at fictional characters basically indistinguishable from a Lightner in any way that matter