Quillette is cynically using the exact same "social-panic" tactics they're criticizing to create exactly your conclusion.
The Q article has exactly two complaints about the facts reported by the media:
1. The media claimed bodies were unearthed, when in fact only scans were taken.
2. The media claimed there were mass graves, when in fact scans only detected masses of individual graves.
However, in "social-panic" style, conservatives are taking these two quibbles over terminology and turning them into an Alex Jones-esque conspiracy to deny the graves existence altogether.
Note also the subtle racism in the article, where they compare a hypothetical instant-response to the murder of white children to the "very odd" response of the first nation people. The implication being that first nations people are incompetent, uncaring, or untrustworthy by not immediately doing a certain kind of investigation.