Sometimes oly lifters use the high bar close stance ass to grass squat as an assistance exercise. More carry over that way for their competition lifts vs say, low bar wide stance PL style squat. This is why sometimes that style of squats is called "olympic style". Hossein rezazadeh does them in the off season for training, there's a few videos of him floating around doing it.
In the off season? I think high bar back squats are a staple of just about every o-lifting program year round.
Anyways, I've been a subscriber to the average broz youtube channel for a while. Super impressive stuff: an icredibly gifted athlete + a great work ethic + a great coach = American gold medal. I can't wait to see this kid in 2012...