Nah genocide isn't my jam... But yes, I believe the Dominion war wouldn't have ended without the virus. The Dominion would have just kept sending ships and Jem'Hadar from the Gamma quadrant.

Edit: btw I dislike the way DIS "unshrouded" section 31. It was much cooler in DS9 where we were left to wonder whether it actually existed or not, or it was just Sloane being godlike in his manipulation skills.