I could have accepted a plagiarized Ep. VII with a Mary Rey Sue if they'd done something decent with Ep. VIII but they didn't and Ep. VIII left nothing for IX to do. JJ is now going to have to create and resolve tension for two movies in one. Thanks Rian.
That's not
entirely true. I mean, there are some snippets here and there, that could lead to something good. For example, Rey is going to, more or less, be the new Luke, off to create her own Jedi order. I doubt Kylo Ren will be completely defeated - probably more like severely weakened, with much loss of support in all ways. This is a good thing, and it would allow the writers to show him gaining control of himself - not just giving in to childish tantrums for the sake of being an edgelord of darkness, but allow them to show him grow into his heritage. We have seen, via extra media, the kind of lineage he has. Vader/Anakin, the powerful force user, the tactical mind, the incredible piloting skills, the mechanical aptitude, and thus showing him evolve into a frightening leader, and truly ruling over the First Order. Similar things for Poe and Finn.
Then again, that should have probably been something in VIII. But, really, there isn't much space for Abrams to work around. At least, not much I see.