He didn’t coin the term but he is the only one I’ve ever heard use the term. He added the “doper” part I think.
As a side note, check out who reviewed the “Red Diapers” book from the link you provided- Angela Davis and Howard Zinn! lol They would know about the subject wouldn’t they? ha
Two of the best books on the subject are by Conservatives who were Red Diaper Babies who saw the light..
David Horowitz “Radical Son”
Ron Radosh “Commies”