Ive thought since the beginning of the What If..series that it ties directly to the MCU.

Its my theory that in the Universe in which Loki "leaves" ( the ORIGINAL MCU that we knew up to that point)…thats the one that falls to Ultron in What If?

At the end of season 1 we see all of these different versions of "heros" band together to defeat an Infinity Stone Ultron. Including a Dr Strange variant that in season 2 of What If.. tries to destroy countless universes to recreate his own.

Its my theory that the Captain Carter from What If is the same that makes up the Illuminati in MoM. And that What If series ties them all together.