Once upon Jean Grey was possessed by the Phoenix Force. Becoming one of the most powerful creatures in creation, she burned bright and fast – and in the process, committed genocide.
She died, an act of suicide. It was quite the thing. The storyline, told by Chris Claremont, Dave Cockrum and John Byrne has become a recognised classic.
Years later, Jean Grey was brought back for the series X-Factor. It was revealed that Jean was never Phoenix, instead her body had been kept in a healing cocoon and the Phoenix Force masqueraded as her. Eventually Jean Grey died again. It's like a habit.
But now… the history is less sure. Generations: Phoenix from Cullen Bunn, RB Silva, Adriano Di Benedetto and Rain Beredo and published by Marvel Comics today sees the young Jean Grey from the past meets the Phoenix version of herself – also from the past, but slightly less from the past.
And much is discussed and occurs between them. And there is nothing to specifically state that the Phoenix is a Jean Grey possessed rather that Phoenix with an imprint, but there is no mention of cocoon Jean Grey. And Jean Grey, internally narrating doesn't even mention this to herself.
Which is an odd thing – unless this is a subtle retcon.
It means that, as far as modern X-Men continuity is concerned, it appears that continuity is returning to the pre-X-Factor state. The various revivals of Jean Grey are being done away with. Apart from that in All-New X-Men. This may not be explicitly referred to. But don't expect any cocoon acknowledgement – or how Jean Grey was revived the first time, for quite a while. If at all.
More time travel! Now! So we can work this all out!