That video was a bit weird, but the clips of Young showed that he was far beyond his competition in high school. I have no idea if he played on the AAU circuit at the time, but, in theory, that would have offered a better glimpse of how he stacked up and, presumably, would have informed his decision to go straight to the NBA.
I saw him play a few times in high school and the fact that he couldn't really shoot beyond 10 feet didn't matter - he was so much more dynamic than everyone he was going against.