What the article is targeting (in a confused way) is a toxic new ideology that is especially influential here in the US. I suggest we call it PEC, i.e., ‘Progressive Except for Class’: it opposes an open-ended set of oppressions, starting with race and sex and potentially including anything except class.
A report from Class, the union-funded thinktank, on new attitudes to race and class in Britain explains you cannot predefine the beliefs and values of a class, it says, and then filter for people whose views correspond to them. Instead, the researchers built their sample on a points system, taking into consideration class identity, housing tenure, education level, occupation, household income, and if and how one might pay a £500 emergency bill.
The “uberisation” of certain sectors such as academia, coupled with general pay stagnation and a public sector pay freeze, have combined to mean that old blue collar/white collar distinctions are no longer meaningful. You can have what used to be called a “middle-class job” and still struggle to meet your basic needs.