The professor might have bigger problems than accusations of racism. Deterioration in one's ability to write and communicate can be an early sign.
Speaking of “longitudinal detection of dementia through lexical and syntactic changes in writing” [which by the way I do fully understand], how does his use of “the blacks” or “the Asians” substantively differ from “blacks” or “Asians” except that one more formalizes a connection with a group?
One might say that of, say, Jewish mothers, uncles or aunts - any old guard relative who says “the Gays?”
Further, to detect deterioration, one first must have some sample of earlier writing from which to discern a difference.
The whole bugaboo about this is that, in however awkwardly or behind the times manner, he spoke a semblance of truth in what he perceives from what he could observe in his daily world. That doesn’t mean he is demented because he used the word “the”.
To condemn upon the first instance because of the use of some ill-defined ‘trigger’ word or phrase is condemnation and censorship - certainly ill fitting in a country where all manner of person is supposed to have free speech.
He could lose half his brain cells and he’d still be smarter and more ethical than leftist trolls.... and 98% of leftist PC ‘professors’....