If you just read the quote in the article it does look a bit silly. The reason why people warned him and why the field of history was so "eurocentric" is because it is extremely difficult to find evidence in the Amazon. Nobody doubts the existence of Tenochtitlan or Cuzco because we have both written sources and archeological evidence. In this context, complaining about eurocentrism does come across as motivated reasoning.
If the Prof says he was warned against this research at the start of his career because scientists believed no ancient groups had lived in the Amazon. Then this is clearly an interesting new angle. Sorry that you found it too "woke".