My guess is: Dean Sue would have informed the parents but Brodhead told her not to call them. He didn't want them in the way while he closed down the lacrosse program and fired the coach that most of them came to Duke to play under. He could then throw these guys under the bus without their (some) powerful mommies and daddies getting in the way and could then show how sensitive he was to the racial politics of the city.
Dean Sue has been there for a long time, I am very surprised that she didn't contact each and every parent asap.
Oh, that would be delicious if Dear Sue can pin the tail of responsibility directly on the Brodhead.