Again, you are out of touch. These HBCUs have always been integrated. Whites, Latinos and whoever else attend these schools. In the early 80s there was even a movie about Jim Gregory, a white dude played by Bruce Jenner, that played quarterback at Grambling St. Since black kids have lost interest in baseball, the baseball teams at a lot of these HBCUs have white and Latino players. The same with the golf teams. These HCBUs have always had white faculty members, administrators etc.
Similarly, with fraternities and sororities. At one time, at PWIs, blacks could not join fraternities and sororities. Therefore, in the early 1900s, blacks started their own fraternities and sororities. If y'all attended Purdue, you may have seen some of these black frats and sororities around campus. And yes, white men and women have joined these organizations.