This came up a few weeks ago. If you look at the dates, "Cartaker" happened only a few weeks after "The Search," so it's not clear if Voyager's
crew would know about the Dominion. Someone like Janeway might know that the Odyssey
was lost in the Gamma Quadrant, but there's no guarantee she'd know that the Dominion was to blame. Federation space is huge. That Voyager
was at DS9 before looking for Chakotay tells us nothing of where Janeway and her then-senior officers were before their mission began.