Mystified by this. Seems to be driven by the fact that they are taking the B787 and so have to try and fill them somehow but are basing them all in YYC with none in YYZ. GLA/EDI-YYZ is a reliable known quantity that they're able to crew from the existing YYZ B737 base, YYC hasn't been served since AIr Transat flew it from GLA a while back.