Yes
No
It's complicated.
She was never meant to be Jean. Ever. They toyed around with the idea before Hope was created. But when Hope was created they always said she was not Jean from day 1. And I know this because I was on these boards when IGN asked that question. And when Cebeluski and Alonso said that she was never a reincarnation.
What's funny is that Jean Grey fans were constantly told she wasn't Jean from Day 1. She turned out she wasn't Jean and now we have to create some delusion to retroactively change history to please some hysteria.
No that scene was a throwback to Cyclops giving Cable to Mother Askani.
Jean is super important, even when she is dead. When she dies all the X-books and the x-men lives change, their world becomes darker. No other death is as big as hers.
She didn't stay dead because she didn't matter. on the contraty, she matters too much. When she is alive all the big players on the X-books change, Wolverine, Cyclops, Xavier, Storm, even Emma.