I don't think anyone's missing the point. First line of the abstract: "We show that faces contain much more information about sexual orientation than can be perceived and interpreted by the human brain". They make a fairly strong, unambiguous claim in favour of their AI. 

If their results have any validity, then evolutionary biologists have some work to do to explain -- given that a major function of the human brain is to interpret human faces -- why faces would carry more (useful?) information than brains are able to interpret.