The team wanted to keep this surprise so secret that not even the actress knew what was happening to her character.
Beware, SPOILERS! Don't keep reading if you don't want to know anything about Spider-Man: far from home
The final turn of Spider-Man: far from home is one of the most surprising outcomes of the Marvel Cinematic Universe - with all due respect at the end of Avengers: Infinity War, which still thrills fans today. Discovering that Nick Furia and Maria Hill are imposing Skrulls caught viewers in movie theaters off guard and, interestingly, the same actors who were shooting the scene.
As revealed in an interview with The Hollywood Reporter, Cobie Smulders did not know that her character had been supplanted throughout the film. Of course, I also didn't know that Nick Furia was actually on vacation.
Literally, a week before the movie came out, I discovered thanks to Kevin Feige that they had shot an extra scene. It was added in post-production. That footage belongs to the first scene that was removed from the movie.
So where is the true former deputy director of S.H.I.E.L.D.? Smulders hopes he is well and has debated the fact that Maria Hill may have been a Skrull since the first Avengers - Joss Whedon's tape - "They can change it that way, but, in my mind, it is not so. No, I know where he is, but I hope he is on vacation somewhere. In this world, he is probably on another mission. "