They stopped posting DOBs because it was too embarrassing
Rather, probably because of all of the stupid emails they were getting, just annoyance, rather than embarrassment. It was by grade, so posting birthdays would be as relevant as posting hair color. It's universally know that private school kids are going to be a year older on average, so other than crying points when we win, or rallying points when we lose, it's just not relevant. HS and College don't go by age, except with some cap regulations, so we might as well be talking about the the weather or paint drying.
