Maybe I skimmed the article and didn't look for specifics enough, because I did not see a bias towards any level of education. But of course I am biased myself, probably using all the fancy words and still making grammatical errors like a fifth grader, and iirc I did not have a native American coworker (aka people with whom I regularly talk and not just write) for 10 years, only other ESLs and some British people.