If Fiend/Orton would be the only cinematic match then I don't see the issue. Maybe they could somehow leave the end of it do be live so that everyone at Raymond James Stadium isn't looking up at a screen during the whole match. I'd just rather see a cinematic match than them doing a straight up wrestling match.
Plus I do like the idea of keeping The Fiend the way he is now, burnt. Let Alexa do all of the talking, even during the funhouse match... or "playground match" or whatever. That would be her spot at WM without worrying about putting her in a battle royal.