I infer it from this part of the article:
This to me means they want someone who understands the experience of being in the racial minority when it comes to race relations. If they were concerned about the teacher being all of the races they would have asked for that. They did not. Clearly a black teacher is qualified in their opinion to teach not only African studies, but Latino and Asian as well. Why do you think differently?
You can understand without having been through it. Its how almost all teaching works. If it did not work, then empathy would not even be a word right.
Also, they did say this...
In order for one to convey the messages and teach the real lessons, the authentic lesson, it has to be someone who lives it and has been there
This means that a white teacher cannot teach it, because they can never understand what its like. But, if a white teacher cannot understand, how can a student unless they have been through the same situation, and if they had, why would they need to be taught about it?