Re: What happened in the Visitor future?
Worf joining the show and the resulting Klingon conflict interrupted the writers' plans for the Dominion arc, which didn't get into gear again until Season 5 (based on Memory Alpha's background tidbits).
Though from the thread title, I thought you meant a different Visitor's future.
Curly: Moe, Larry, the cheese! Moe, Larry, the cheese! (Horses Collars, 1935)