I am far from expert on Critical Theory, but I know enough to know that this article is a gross distortion of it. For starters, CT is concerned with the problems inherent in all ideology, as a prelude to learning what can be done about that. It is critical of Marxism and Liberalism--and Fascism.
These days. no ideology even purports to be "objective truth." That makes 'debunking' Critical Theory as a legitimate critique of any ideology for denying the existence of objective truth pointless drivel.
If there is such a thing as objective truth, it can only exist in science. It cannot exist in any moral claim because all morals are based on beliefs, not facts of material existence. All beliefs--sacral or secular--are intrinsically, profoundly subjective.
Contradictory beliefs can only result in "contests of power" (from Michel Foucault). To claim that only 'the other side' in such a conflict is seeking to impose its beliefs on the other is to be grotesquely unaware.
Postmodernism, which is not the same thing as Critical Theory, has to my mind made the case that "objective truth" is not possible. That is, for any human being subjective influences unrelated to the matter at hand will always impact our mental processes, bending them in particular directions of which we are not--cannot be--aware.
As for the classes themselves, the U.S. military has been requiring such classes since the 1970' As a veteran, I attended them. To suggest that the classes themselves are more harmful than the problem they are intended to ameliorate is nonsense.