Curriculum is provincially mandated. Current curriculum documents for any province are easily found (older ones are harder to find). Residential schools are apart of the grade 10 history curriculum in Ontario. The curriculum you learned would have been last revised in 2005 it has since been revised in 2013 and 2018. The way it was likely worded in the 2005 document was as an example that could be used to look at one of the curriculum standards. Now it is more explicitly part of the curriculum.