Will they ever add "special characters"

I would actually love it if they did that because there have been some great celebrity cameos on the Simpsons. One of them that really stands out in my mind is Lucy Lawless as Xena from one of the Treehouse of Horror episodes. I think it would be great to have Xena, Bart as Stretch Dude, Lisa as Clobber Girl, and CBG as the Collector for a Halloween event. Another one I'd like to see is Conan O'Brien, I'm not sure how that would fit into the game but it would be cool seeing how Conan was a great writer/producer for the time he worked on The Simpsons and he also that cameo where Bart was on his show. Unfortunately I imagine they don't have much interest for the time being in adding celeb characters to the game.