AC is unlikely to route you via YYZ just because, assuming everything else is on time and you are not going to obviously misconnect.
FWIW, last time I connected in to YUL from YOW the inbound was 30 mins late, then we waited 40 minutes on the ground for a gate at the Jazz satellite terminal building, just idling around in a DH3, because ramp crew were apparently not happening. I had to sprint so hard to make my TATL that I was soaked like I came out of a shower. I decided YUL could take a break for a while - it is on the "only if I am already there / take the train" bucket until AC can figure out a way to make flying YOW-YUL faster than driving.
Hopefully you'll have better luck.