Do you mean they were wearing t-shirts that had things like "homecoming queen 50 years in a row, most members, highest GPA" written on the t-shirt during rush? If so that's pretty obnoxious, but they could be just as obnoxious on their website. Still, it's not out of the ordinary for schools to have rules about sorority members not wearing letters or "identifying articles" (i.e. party shirts, old bid day shirts) while rush is taking place. Maybe something like that should be instituted.
As far as the grade thing, definitely NOT cool. I don't know why anyone would join a group who acts like that, quite frankly...