Thank you for the clarification.
What I imagine McWhorter is referring to is mainstream news/opinion outlets that are trying to turn DiAngelo's styles of philosophies into "conventional wisdom" through their curation choices and featured editorial pieces. So I can understand his frustration, although I would concur with you that he is perhaps overdramatizing the scope of it.
Your reference to DiAngelo's work being "popular" was indeed open-ended, in how I interpreted it. Just because someone makes the best-seller list doesn't mean they are right...or particularly talented. Thousands of people could be buying her book for any number of reasons...including, but not limited to, morbid curiosity (which is the reason why I bought it, albeit a used copy of it) or curriculum mandates.