Do they? I mean, that's the perception, no different than when Cal got all those cream of the crop (one & done only because of the NBA rule) prep dudes.
Fact of the matter is, they were destined for the NBA and the aforementioned contracts with or without K or Cal. I find it extremely difficult to ever buy into the premise that spending one year there had much to do with them getting to the league, let alone staying there. The marketing/pitch certainly works for the programs/schools that are quite fortunate though.
There's a reason why they are called "blue chippers."