I know this conversation has slowed, but I am a Washingtonian and it has historically always been pronounced Gone-zah-gah. And if you look into the history the school was founded by the Jesuit priest Joseph Cataldo who named it after the Italian Saint Aloysius Gonzaga. But for some reason the pronunciation has changed due to people coming to the school who are probably just from different regions and didn't learn the proper pronunciation. Soo whatever, tomato, tomahto.