His racism claim does have some merit to it. There have been studies done that show that black airman are far more likely to face punishment than white airmen compared to the other branches.
Here's a link to the full study.
Anecdotally, my unit was notably racist and sexist. It was all male and probably ~90% white. We would have indoc and none of the women would pass. Even if some did they would find some way to wash them out. I heard my leadership talking before and they said women were too much of a problem. The majority of the people that passed were white male airmen. It was one of the reasons I decided to separate. It was a very toxic environment.
All that being said. I still enjoyed my time in the Air Force and that was a great speech. We need more leaders like him.