From what I can guess, if the Terran Empire HAD continued to the DS9/VOY era, there probably wouldn't be any treaty with Cardassia, no DMZ and therefore no Maquis; even if a MU Voyager was taken to the Delta Quadrant, surely the mirror Janeway would go "Meh, don't care about the Ocampa." and used the Caretakers array to go home, leaving it to the Kazon.
Just a theory.