I tend to agree with Mav. Almost everyone's muse likes new and shiny things, which was what TFA brought us. Most people did get bit with new bunnies - Luke or LM centric or not. Which is fine. I personally love the fact that, at least until May 2017, we can freely insert Mara into the new canon. And, maybe, if they give Luke a new lover/wife in the new canon, maybe I will like her and write fics with her, maybe I'll hate her. It's impossible to tell. Maybe they won't mention a wife by name (Padmè got one very indirect mention in all the OT). Maybe they will let the books fill in that role if there's need for one (IE if Rey is Luke's daughter). And, I don't think LM will die out completely either, even if Luke is given a new wife everyone loves. LM stories did take a hard hit after Mara died in the books. Yes, there was a bit of resurgence due to a number of factors (a couple of very prolific writers, the fact that a number of us kept in touch over the move of 2012). But I think most of us can still love the old and the new canon and write in both. And, as Mav pointed out, there are still FRIENDS fanfic being written and other shows and movies and books that have long since ended that still get fanfic written about them.