He is telling us that the roshei yeshiva clearly understand the issues and told him that it is naarishkeiten until someone brings forward some real data.
Have you gotten a chance to read his original article yet? (You originally criticized it without reading it, so it’s a fair question.) In it, he agrees to age gap theory. So, if he says that the roshei yeshiva understand the issues, he means that they agree to age gap. Unless you’re also accusing him of lying, in which case I can’t understand why you would be so proud to be a member of the same klal Yisroel as him.