How can Madelyne Pryor attempt to posses Jeans corpse if The Phoenix Ressurected her already?

In a recent X-Men issue, Madelyne Pryor returned as the Rec Queen, leader of The Sisterhood of Mutants, she attempted to take possesion of Jean Grey's corpse, but Cyclops, knowing this, switched Jean's coffin with another, but how could he have done that if The Phoenix already ressurected her and they've gone to find all the missing pieces.