The comment you reply to describes people who label others as narcissists for frivolous reasons (they disagree with people, want to dehumanize or blame, want to protect their own ego).

We haven't established that they're the same people or correspond with one another. I think both groups simultaneously exist. I know I've witnessed the second group in real life, though I wouldn't dare claim it's everybody who says they've been abused by a narcissist.

There's zero indication that the GP as approaching this from the perspective of an aggrieved narcissistic parent. There are certainly some people who were actually "raised by narcissists," but the point is that it seems like a lot of people weren't use that concept as cover for validation and to air unrealistic complaints on social media.

But it's not a singular story, it's many thousands of independent stories. That link only provides the other side of some of them.