I'm only a lonely P, but every single flight I've flown on AC or QK that has had executive class seating has been available for me at T-48 hours for an eUpgrade (and sometimes a lot closer to departure than that). This includes:

YWG-YYZ (twice)
YYZ-YQR (I upgraded this)
YYZ-DCA (I saved my points and upgraded with an LMU)
YQR-YOW (I upgraded this)
YOW-YYC (I was two points short so I upgraded with an LMU)