There were rumors about an episode where Q sends Voyager back to the Alpha Quadrant and tries to convince them that they're better off in the Delta Quadrant because the Dominion had won.
http://www.hack-man.com/StarTrek/TREKFAQS/voy.txt
" 16. “Quartered” - Q makes his third appearance as he temporarily brings the Voyager back to the Alpha Quadrant, where he tries to convince the crew that the Federation has been defeated by the Dominion and that they’re better off in the Delta Quadrant. This show will celebrate TNG’s 10th anniversary and will feature part of the TNG cast.
That would have been an interesting episode to see.
There seem to be quite a few opportunities for the Dominion to appear in VOY, as that link suggests.
"5. “Two Way Mirror” - a complex synchronic mirror universe show that will start in a Voyager show and end with the following week in DS9 show or the other way around."
If there was an interest to display the mirror universe version of the Dominion. Tuvok was already established in the mirror universe, so all that were needed were the rest of the VOY crew.
"8. “The Privateers” - a group of daring alien mercenaries helps Voyager out of a tight spot only to make impossible demands in return."
This may have been meant to been alien of the week, but could have been reworked into being about a group of Jem’Hadar or Vorta that broke away from the Dominion.
"12. “Retaliation” - after a Maquis crew member is killed during an away mission his buddies embark on an unauthorized reprisal action against the assailants."
This story would make sense with the ongoing Dominion War as a backdrop and the assailants were the Dominion themselves. But if the Maquis crewmembers get reprimanded, then it would have to lead into this episode…
"7. “Cascade Clause” - a major Maquis mutiny rocks the entire ship after Janeway relives both Chakotay and Torres of their duties."
And we know that a showdown between the Starfleet officers and Maquis officers never came to fruition outside of being a holodeck program.