MCU - 10 Ways Avengers: Endgame Sets Up Phase 4 & Disney Plus
9. Guardians 3 Is About The Search For Gamora
As addressed with Black Widow, the Soul Stone deaths cannot be reversed. They were, however, gotten around by bringing the Gamora of 2014 into the new present-day timeline of 2023.
This is a Gamora who never met the Guardians and went through all the character development, and, in the midst of the battle, she manages to disappear.
The Guardians' part in the film ends with them joined by Thor, and Peter Quill looking at an image of Gamora that simply says 'searching'. Whether Thor will actually form a part of Guardians 3 is unclear - there's still a lot of time between now and then for things to have changed and them to explain he's gone elsewhere - but the search for Gamora should.
She's out there, and there's no way Quill will stop searching for her. Vol 3 ends the story of these Guardians, and for a franchise all about family, putting it back together is a nice way to go out.