Did you even read the article? That statement is prefaced by "According to what seems to be a widely accepted origin story of Bitcoin, ...", meaning that's what many people assume.
Then right after, his thesis is to contrast that: "I would argue that Satoshi is actually Nick Szabo himself, probably together with one or more technical collaborators"
Did you read the article? He is saying that Satoshi was someone with experience as a researcher, someone who had authored many articles in the past. The Bitcoin whitepaper and Bitcoin itself suggest nothing of the sort; they suggest that Bitcoin was the work of someone with limited research experience.
Then right after, his thesis is to contrast that: "I would argue that Satoshi is actually Nick Szabo himself, probably together with one or more technical collaborators"