That's true. Montreal just upgraded their rolling stock: (The MR-73 didn't owe them anything https://en.wikipedia.org/wiki/MR-73) but the new cars (https://en.wikipedia.org/wiki/MPM-10) have the doors in the same place as the MR-73 cars.

Admittedly I hadn't thought of that, but I don't think there's that much variety in rolling stock for a given location, and when speccing out replacements I don't think it's too much to ask that the doors are in the same place (cars are purchased in dozens...), maybe I'm wrong. Montreal is a much smaller network than New York.