The Skrulls have been working with Fury
The post-credits stinger for Far From Home contained, arguably, one of the biggest bombshells of the MCU. The Nick Fury and Maria Hill who spent the movie working with Peter were, in fact, Talos and his wife Soren–Skrulls we met back in Captain Marvel. This is hugely significant for a few reasons, not the least of which is the fact that it tells us the Skrulls have been active in the Marvel Universe since the ’90s–and they’re working hand-in-hand with Fury.
This means that at any point in the MCU’s timeline after Captain Marvel, any character could have been replaced by a Skrull for any reason. Of course, the threat of Skrull-replacement in the MCU isn’t that dire–the Skrulls are friendly in this universe, not evil–but still. It does provide a nice “get out of jail free” card for any and all inconvenient moments writers and directors may want to address from movies past somewhere down the line.
Also, moving forward, this means we can expect to see Fury and the Skrulls–who, by the looks of things, have a very well outfitted space station–working together to monitor for threats.