I've been very curious about this myself. I've been going back and forth between ATL and SNA almost weekly since October, mostly flights have been direct (737-700).

The flight crew has always left the AVOD on until after we've landed, sometimes right until we've pulled into the gate (once, after we parked). This week, they announced that we were on final approach and they turned it off. I thought this was very strange as we were still in the air for a good bit of time.