Throughout the first two Phases of the Marvel Cinematic Universe, S.H.I.E.L.D. were integral to the overarching narrative. It was the surprise post-credits cameo from Samuel L. Jackson’s Nick Fury in Iron Man that set the stage for The Avengers, with the shady government-sponsored offshoot playing major roles in Iron Man 2, Captain America: The First Avenger and Thor.
Later films explored the origins of the outfit by revealing Peggy Carter as a founding member and establishing that Hank Pym and Howard Stark also had ties to the organization, before the entire thing imploded during Captain America: The Winter Soldier when it was revealed that H.Y.D.R.A. had infiltrated its upper echelons decades ago, and were manipulating S.H.I.E.L.D. for their own means.
However, the post-credits scene of The Falcon and the Winter Soldier has hinted that the remnants of the organization still exist within the MCU, after Sharon Carter was offered her ‘old position’ back. While the freshly-announced Power Broker has a CIA background, the mention of her family’s legacy would indicate that it’s the other secretive espionage agency that was being referred to.
It would make sense for the government to try and pick up the pieces of S.H.I.E.L.D. to try and right some wrongs, too, even if S.W.O.R.D. has already made its presence felt during WandaVision, with the stinger of Spider-Man: Far From Home further outlining that Nick Fury has now decided to take himself beyond the stars to keep his one good eye on Earth. Sharon has been rumored for a return in Secret Invasion as well, and a single brief scene at the very end of The Falcon and the Winter Soldier could be teasing big things to come from the Power Broker.