This is a post written by David Thorstad, a philosophy professor who maintains a blog for criticizing various tenets of effective altruism called Reflective Altruism, as part of a series of on human biodiversity (HBD), a modern iteration of so-called race science. HBD, of course, isn't typical fare for EA, or any of its championed causes. Yet it has, to much controversy over the years, been recognized as a subject of interest among prominent thinkers associated with either the effective altruism or rationality communities, or others writers they've been affiliated with. This latest post in Thorstad's series provides a critical overview of @Scott Alexander's history of engagement with said body of ideas, both on his current blog, Astral Codex Ten (ACX), as well as before then, such as on his previous blog, Slate Star Codex (SSC).
My reading of the post (which is contestable) is that he chose the people as a sort of joke about "here is a controversial or absurdly in-group person I like on this issue". I can't prove that reading is correct, but I don't really see another that makes sense of the post. Some of the people are just too boring choices-Yglesias, for the joke to just be that the list is absurd.