I did a search, found a couple of prior incidents at other places, but nothing to indicate a nation-wide issue with SAE.
You are the one making the accusation, so it falls upon you to provide evidence backing up your assertion.
Racist fraternity chant may not be limited to University of Oklahoma
http://www.latimes.com/nation/la-na-oklahoma-fraternity-racist-chant-20150311-story.html