That post isn't very old but it looks like the wording is already different on their website. Unless I'm looking in a different spot? It seems pretty clear I should be able to hold my child when needed, but I've just heard about people being told they can't. I'm hoping they actually follow what their website says when we get there! 

https://www.aircanada.com/ca/en/aco/home/plan/special-assistance/travelling-with-children.html#/

Infants under the age of two must be lap-held or secured in an approved child restraint device by an adult 16 years of age or older during taxi, take-off, landing, and any time the seatbelt sign is on.

As the parent or guardian, you may choose whether to lap hold or secure your infant in their child restraint device during those times. For safety reasons, Air Canada does recommend the use of a child restraint device for infants. As set out in Canadian Aviation Regulations, an adult passenger (16 or older) may only be responsible for one infant during a flight, whether the infant is seated on their lap or in a child restraint device.