I don't believe that ensuring children conformed to the current cultural norm was or is unique to Canadian schools.

My mother was left-handed and was forced to write, etc with her right hand by her Dutch teachers, as were all other lefties. Force included bloody knuckles from rulers wielded by teachers and other corporal punishments. I've heard similar stories from other lefties from other countries.

Schools were (are?) about teaching children to confirm as much as teaching them reading and math, etc - I think that was a pretty universal thing in previous generations. Just because your experience was in Canada doesn't mean there was anything specifically Canadian about it.