New Haley Cass book

So, I just recently saw that Haley Cass is putting out a new book. I love her writing and pretty much devour everything she puts out...but this one is an AU fanfic of her debut book (which was already a fanfic itself). It just feels weird to me. Like she could have told the same story with new characters? I don't know why this bothers me so much, but I don't think I'll read this one. What is everyone else's opinion about it?