First, regarding the YYZ-CUN flight, I suspect it will be a good ol' L1011-15.
In YMX, flights to CUN are operated by L1011-15 (C-FTNL last Sunday), and there is no reason to operate smaller aircraft on this run out of YYZ.
Regarding the A313 (C-GFAT, really), it came in YMX late December. First flight was supposed to be last week to Port of Spain (out of YYZ) I think but I may be wrong on this one.
And No PTV as mentioned Slawko.
Other A313s expected in March/April.