> I suspect a 20 year old was behind it.

Yudkowsky wrote them from 2006-2009, so he would have been in his late 20s.

> because people are aware that the studies referenced in there turned out not to replicate

The Sequences are about pure reasoning, not about results from "studies". They are very much about how to analyze studies and about the fact that you should care whether they replicate.

In fact, I can't even recall any such "studies referenced".