HBCUs have a tendency to do that to organizations.
A chapter that is predominantly racial and ethnic minority will tend to operate differently than a chapter that is predominantly white.
The NIC (or were they IFC back then?) fraternities that colonized at HBCUs saw it firsthand. Many of them were students who wanted to be in an NPHC frat trying to change the structure of the NIC fraternity to mirror what they aspired toward--and then some of them eventually joining an NPHC frat if the rules and new member selection allowed them to. I don't recall an NPC chapter ever being chartered at an HBCU.