The GP didn't claim something bad was going to happen to them if they followed the link. They simply stated it didn't load under uMatrix.
uMatrix doesn't stop bad things from happening to you. It's simply browser add-on software that can block specific types of content. In this case, probably trackers or ads. Perhaps the GP is attempting to maintain their privacy. We can't know their motivations with certainty because they never made them clear.
The person that put the page together might consider testing whether or not it loads under uMatrix before exposing it to the world.
How is it the page author's responsibility to ensure it loads under a third-party plugin you loaded to block content? It's an entire article made of advertising, for obvious reasons (it comments on the advertising). Who knows how or why or what umatrix is blocking here under that user's settings?
No thanks.