You have posted the MCT for JU-JU at BEG. OP is connecting at CDG from AC-JU. What matters is what AC posts as a MCT at CDG. If OP's ticket doesn't meet the AC MCT at CDG, his bags won't be interlined. If he does not have checked luggage, AC may or may not board him at YUL.

I would obtain a definitive answer from the TA.