SPOILERS AHEAD FOR SPIDER-MAN: FAR FROM HOME
One of the end credit scenes for Spider-Man: Far From Home included a reveal that Maria Hill and Nick Fury were actually Skrulls in disguise. It shows the real Nick Fury in space on a ship with the Skrulls. The implication is that Fury is up there creating S.W.O.R.D. It will essentailly be an even more widespread and secretive S.H.I.E.L.D. that will operate on a galaxy-wide scale. This has led many to believe that Fury has been a Skrull since the time of the Captain Marvel movie.
Many fan theories have supported this. One being the fact that it is made known that his friends call him Fury and not Nick in Captain Marvel. Fans have gone back to find all the moments that people have called him Nick and he does not react the way he did with Talos. Also, he mentions being unable to eat toast cut diagonally in the movie during a comedic scene with Danvers. Fans have found clips of him cutting a sandwich diagonally in Avengers: Age Of Ultron when he is talking to the Avengers in Hawkeye’s secret family home.
Despite all of the fun research And theories from viewers, director Jon Watts gave an interview stating that Nick has been himself all the way up until the funeral of Tony Stark.
While it kills all of the rumors and fun speculation, clearly Marvel does not want to make such a bold claim that could potentially make all previous Nick Fury appearances become meaningless. If he was a Skrull this whole time, all of his relationships to the heroes and S.H.I.E.L.D. members would be non-existent.
With San Diego Comic-Con and D23 on the way, we are sure to get some more insight on Phase 4 of the MCU soon.