I also find it weird that it would be YYZ-BEY, everytime AC tried to launch this route it was from YUL, and BEY fits perfectly in their hub definition for YUL of targeting french speaking communities.
As for no 787 out of YUL, they do have YUL-PVG launching using a 788, and it was mainly that the 787 is "too much" of a plane for YUL right now in terms of range for european destinations, compared to their A330 fleet (albeit missing one for the next few months as per other thread)