Odds are that you haven't even heard of the Canadian Residential School System before. But upon hearing some bad stuff about it your first impression is, I'm not yet ready to say categorically that this whole thing is bogus. But let's have some healthy skepticism here...
And you think that anyone else should care about your uniformed opinion?
Before dismissing the overall story I strongly recommend verifying that they existed, natives were forced to go and live in these schools (hence residential) by law, there was widespread physical and sexual abuse, the Canadian government has admitted that they constituted genocide, and literally thousands of people have filed private lawsuits over what happened there. There are literally so many cases that there is a department of the Federal government dedicated to helping sort them out, and there are questions about whether the Anglican Church should be allowed to go bankrupt from liability over claims.
About individual claims, that is a question. I have personal reasons for suspecting that high levels of death were not accidental. But the levels of drug abuse are high, and I do not have to look far to find people I have known who have eg heroin addictions. With addicts it is sadly sometimes hard to tell what is true and what was made up. (It is hard to tell if they know the difference in fact.) So there are definitely going to be people who "remember" things that didn't happen.
But that doesn't stop the actual facts from being shocking enough without adornment.
Cheers,
Ben