Re: Why the 1970's?
It's also repetitive and cliched. But I think the young Jean needs to be featured at some point in the sequel most likely. The scene in TLS needs to be expounded upon, because it's a good plot device to set things in motion. Maybe manifest the White Phoenix and see her live to the full Phoenix potential in an X4 or beyond. Let's face it, we want to see Apocalypse, but more so, we want to see the Phoenix done properly in all its glory, even if it means abolishing the OT with the alternate timeline.