Yeah, that's an idea that we've all been throwing around, but I'm afraid there isn't a lot of evidence of it being true. The only real thing I can think of that could make it possible is if Jean left a piece of her in Emma to bring her back to life, which would make it possible for her to merge with the Phoenix like she did in Endsong. But that's not enough to discount other things like the 'push' and Jean's actions in Endsong. So no, I don't think that's the case. It's a possibililty, but a remote possibility at best.
"Sometimes you've gotta wreck the truck to get the insurence money to make the truck payments." - Larry the Cable Guy