You know what this means...

So it looks like Lupita Nyong’o was supposed to be in Endgame at some point.

If there ever is an A-Force style film, it probably will happen in a film in which has a female lead attached to it. In this case, I believe Captain Marvel 2 will be that film. Besides Carol Danvers, the film will probably include Ms. Marvel & Photon (after their Disney+ appearances) & who knows perhaps She-Hulk, assuming that series happens before Captain Marvel 2. You only need a few more heroes to form a team, and if Captain Marvel 2 is set as a cosmic film, I think the rest of A-Force will come from the Guardians & Eternals casts.

I once thought A-Force would include a majority of the female characters but now I don't think so but will concentrate on only characters connected to Captain Marvel and her cosmic story. I think Captain Marvel will adapt the Secret Invasion storyline, which could be seen as a 2nd part of the Kree/Skrull war in the MCU. It could also introduce a fellow Young Avenger, Hulkling as the Skrull son of Wendy Lawson in which A-Force goes on a mission to find & protect. Perhaps She-Hulk is the character that gives the kid his nickname. Any case, if Feige wants to introduce another member of Young Avengers as well as providing a reason for A-Force to exist I can't think of any better reason than do it in Captain Marvel 2.

Black Widow is the one for certain I would have wanted to see in that scene. The moment, though, was just a little too convenient, as far as all the women (and Peter Parker, haha!) being there at the same time.