While this is all wild speculation I think it is a very well possible. Marvel has recently seen the light as far as doing some course correction as far as lack of women and people of color. How ever there still isn’t a Black women led film.
In the current run of the comics (spoiler alert) Jane Foster has taken the mantle of Thor. Jane is played by Natalie Portman in the Marvel Cinematic Universe. However Portman has exited the franchise.
Tessa Thompson has been cast in the role of Valkyrie in Thor Ragnarok. I’d imagine this is the last Thor film. Steve Rodgers seemed to put the shield down at the end of Civil War. We haven’t seen a fourth Iron Man film. I’m willing to bet we will see new people pick up the mantle going forward.
So with all of this being said this being said Ragnarok could leave the door open for a solo Valkyrie film and taking the reigns as the lead Asgardian on the Avengers as well.