I think we’re going to see Jean/Phoenix in live-action in some form again. Because in Dark Phoenix, Jean gives a voiceover at the end of the movie saying: “
This is not the end of me or the X-Men. Its a new beginning.”
I talked to ViewerAnon (one of the leakers of Multiverse of Madness) who saw a screening of the movie in early 2019 and he said that line wasn’t in the version he saw. Simon Kinberg in the commentary confirmed that was a last minute addition. So that line was likely added after the Disney merger was finalized. In hindsight, it is clear that line was foreshadowing as Patrick Stewart said that his conversation with Feige happened in late 2019. Just a few months after Dark Phoenix’s release. Like I said earlier, Marvel secretly introduced the M’Kraan Crystal/Panoptichron in What If. Here is an article about it:
https://screenrant.com/xmen-mcu-loca...-if-introduce/
Speaking of the MCU Spider-Man trilogy, No Way Home adapted elements of
One More Day. Spider-Man fans generally hate that storyline but the movie used its elements to great effect. So here is a fun/crazy idea: What if Marvel Studios does the same thing and takes elements from a hated X-Men story but uses it in a cool way? Hear me out.
What if the Deadpool movies become “Cable & Deadpool” movies instead, like how the Ant-Man movies becomes Ant-Man & Wasp movies. Rachel is introduced as the older sister of Cable and their origin is explored. They are revealed to be the children of Scott and Jean, who have inherited the cosmic power of their mother (which emanates from Cable’s left eye). Hope had also inherited this power from her father.
However, it is later revealed that their mother/grandmother isn’t really Jean. The Jean we saw at the end of DOFP was a clone created by the original Jean/Phoenix at the end of the Dark Phoenix movie when she flies back to Earth. Jean did this to make Scott happy while she continued to fly through space as the Phoenix/Dark Phoenix, consuming stars throughout the cosmos relishing in power.
Jean grew more powerful with each star she consumed. Eventually, she evolved into the White Phoenix and ascends into a higher plane of existence in the White Hot Room. But before her final evolution happened, she carelessly destroys the Shi’Ar home planet. Lilandra leads the Imperial Guard to Earth to kill Cable, Rachel, and Hope to prevent another Phoenix from raising in a live-action adaptation of “The Phoenix Must Die” and “End of Greys”.
Basically, it is the Phoenix clone retcon but in reverse. The Dark Phoenix that destroys a planet and “dies” is the real Jean. While the Phoenix-created clone is essentially Madelyne Pryor.
I should note, that this is NOT a theory or anything. Just me having fun with some ideas.