They had to do it x-side because they ruined her over mutants. To lower their numbers dramatically, instantly for the future of mutant stories and to push Bendis' Avengers team. I wish this lie that Wanda was only ruined A-side would stop. They planned this all company wide on the writer retreat. And some of the same writers have written both sides.
Wanda will be back in books when an editor allows a writer to do it. It doesn't have anymore special agenda than that.
X-books have a lot going on without her. Not really for it no. It's about House of M wishes anyway. Not really about her development.