That means five years will have passed since Guardians of the Galaxy Vol. 2’s release, the longest gap between any same series MCU movies.
Assuming this production update is true, that means we shouldn’t expect Guardians of the Galaxy Vol. 3 to come out until 2022.
Currently Thor: The Dark World and Thor: Ragnarok hold that record with four years.
Maybe Kevin Feige and the other MCU bigwigs shifted things around and found a way to make Guardians of the Galaxy Vol. 3 fit better later in Phase 4, but given how popular these characters are, one would imagine it’d be better for them to return sooner rather than later.