This is an interesting thread, because he makes the motte and bailey explicit in a way they're not usually careless enough to do.
No one denies that the residential schools were rough, that the kids who went there were probably kind of sad, and that some of them died, due to contagious disease mostly. That's all very unfortunate but doesn't amount to much more than "kids get homesick at boarding school, discipline back then was often severe by modern standards, and medicine was primitive especially in remote areas." This is the motte and it isn't all that impactful because none of it is all that different from conditions that white kids lived through at the time, particularly in remote areas.
But it was very specifically the claim of mass graves due to deliberate genocide that supercharged this issue back in 2021, with the implication that the residential schools were actually a cover for a policy of systematic extermination. At least I assume this is the charge, as they keep saying "genocide" and that's what genocide is commonly understood to mean. This is the bailey.
The problem is that there is no evidence for mass graves. The few times that they've been investigated no bodies were found. At the Kamloops site they deliberately refuse to even dig, which strikes people as suspicious. So people ask questions. It's only natural to want something more concrete than "because I said so" when you're being accused of genocide.
So they then retreat to the motte of "well things were hard in the schools", and okay, yes, they were, but that isn't genocide. But the implication is that anyone asking for evidence in support of the genocide claim - anyone attacking the bailey - is engaging in "denialism" that the schools even existed or that conditions in the schools were often not ideal. Which literally no one does.
This entire debate comes down to one question. Is the Canadian government guilty of a deliberate, systematic policy of genocide? Did it set out to exterminate the First Nations via the mass murder of their children? That's it, that's the issue, that's what we're fighting about.
And there's a very high bar of evidence for proving something like that. At a minimum, you need a whole lot of bones.
Got any bones out in that bailey?
There is an extreme level of cognitive dissonance in Residential School denialism. Across Canada, not just at Tk'emlups, people were harmed and permanently changed by residential schools and yes people even died, it's been known for generations.