Usually in Star Trek, when we see a glimpse of the future, it doesn't really count. It's just an extension of the logic of the current season. I don't know how much the writers knew of where they were going at the start of the fourth season, but it seems to me that with the Klingons in control of the station they were able to win the war on their own, perhaps by holding the wormhole so successfully that they were never able to establish the solid military foothold they found on Cardassia. It almost seems in this episode like the future would have been better off if Ben had died. Then again given 'The Sisko' and his holy mission, either this really is just another throwaway future like All Good Things, or the Prophets were aware of this timeline and knew how it would turn out.