I think the array of, mostly negative, comments to Ms. Silver's article answer most of the issues—e.g. what defines a "black" student, why presume all such are affected the same way, & how will such treatment carry over into the "real" world workplace?
For myself, I don't support premise 1. It's as simple as that. Lenient grading for students who suffer from conditions that make it harder to do well on test simply leads to universal lenient grading, save perhaps for a fortunate few. Which college students, after all, don't experience periods of depression, alienation, loneliness, stress? Then don't even start on logistical issues like financial woes, need to work, etc.
The notion is absurd & if Prof Klein had just ignored the e-mail or politely declined I'm certain he would not have been disciplined.