Just so I understand, is this article saying that in fact the revelations about unmarked graves at Catholic institutions in Canada remain unsubstantiated? That

Just so I understand, is this article saying that in fact the revelations about unmarked graves at Catholic institutions in Canada remain unsubstantiated? That the findings that caused the outrage were in some way preliminary and did not stand up to further scrutiny? I'm trying to understand if it is saying this about some (small) subset of such news, or in fact about the whole wave of news. And if that's right, is that corroborated by other sources? The original news was huge (and of course it would be), this seems quieter so I'm just double checking I understood it right.