Some programs do, some don't. Most high major D1 level kids have personal trainers, and they put in quite a lot more time on basketball skill training, and strength and agility training, than most on here would ever fathom they do. And then they play a lot of games.
Where they're missing out, most of them anyways, are team skill development from team practices.
So if a kid doesn't play for a school team that has normal team practices, and then plays typlical high level AAU ball, they won't learn things like help side defense, screening and using screens, moving without the ball, keeping spacing...
AAU has basically always been like this. The deterioration of knowledge of how to play the game, probably has more to do with school ball degrading. AAU has always gotten a bad rap, and deserves it in some ways. But if players are becoming less fundamentally sound, less able to play good team basketball...its probably not AAU's fault.
AAU only runs from April 1 to July 31...for most high school kids. What are they doing from August 1 through March 31st?