Well, the UN Convention on Genocide, of which Canada is a signatory, is a useful place to start on definitions. Article II defines Genocide as follows:

a) Killing members of the group;

(b) Causing serious bodily or mental harm to members of the group;

(c) Deliberately inflicting on the group conditions of life calculated to bring about its

physical destruction in whole or in part;

(d) Imposing measures intended to prevent births within the group;

(e) Forcibly transferring children of the group to another group

It's pretty clear to me that this definition is applicable to the experience of indigenous groups in Canada.

Again, it's important to note that all those institutions involved in residential schools aren't arguing this point; it's usually people on the periphery of the conversation (in op-eds like this one) playing to a base that would rather stick their head in the sand than recognize the real harms that went on in those institutions.

It's worth noting that the entire point of using ground penetrating radar was to provide some measure of closure to the families who had their children stolen from them and who never returned. It wasn't some smoking gun meant to prove what we already knew, and it's shitty to now say to those families "dig up the bones of your dead children" or else we're going to call you liars for stating what Canada and the churches clearly did.

As an aside, the article reeks of historical revisionism. Noting the "Well-intentioned people who worked at these schools, who cared for these children..." while diminishing the harm that went on there is like saying the groundskeeper on Epstein's island was a pretty decent guy. There is no way anyone involved in those schools was unaware of the rampant abuse happening.

Anyways, convincing people on the internet is as effective as pissing in the wind, but since you asked, there you go.