What everyone means when they refer to "grievance scholars" is the same group of people that were popularly called S.J.W. (social justice warrior) only a year ago, except with less popular baggage and a more academic tone (which might not last once popular personalities get a hold of it). I don't know what the technical requirements for something to be a real label are, but I can confidently say that it is a real group of people. As reluctant as we all are to admit it, I think the "Jordan Peterson" reactionary movement has made the jump from YouTube personalities to academia, and although they might not want to be associated with their origin story, all of the language and concepts are coming along.
>Judea Pearl thinks that DL is nothing more than curve fitting. Is he a greivence scholar?
This is a red herring, because although many off-mainstream scholars have literal grievances, their primary subject of study is not the fact that they do.