Dave, I don't know the actual source (study) but on a number of occasions I've seen/heard that studies have shown that most college players who sign pro contracts and leave school early fare far better if they wait until they've played their junior year. Better in this case meaning making it to the NHL or at least playing most of their pro career in the AHL. Now for most of your really high end skilled (NHL draft) players that start college at younger age than most other guys, it probably doesn't matter that much when a kid leaves college. Those guys are probably going to make it to NHL/AHL anyway. But for guys that aren't drafted and sign free agent contracts, the ones that do well at the pro level are those who stay through their junior year. Many of the ones that leave earlier evidently languish in the ECHL or maybe eventually make it to the AHL. Not many make it to the NHL; some do. Not just my opinion. I've seen/heard it stated a number of times.
In Bindulis case, he went from juniors (NAHL) to less than a full season with the Lakers (injury problems). I wish him the best and hope he makes it to the NHL some day, but I would have been surprised if he played any place other than the ECHL for most of this season (and maybe even for one or more seasons to come). I just think he would have been better off playing another season or two with the Lakers where if nothing else he would have gotten more experience playing at a higher speed (than juniors) in the college game before turning pro. Additionally, for these kids that commit to playing Div 1 college, it would be nice to see them stay in school longer to better their chances of eventually getting a degree. I think it's far more likely that a kid who played 3 seasons in college will go back and finish his degree than a kid who plays only 1 season (or even 2).
If these kids that sign free agent contracts stay through their Junior or Sophomore years, they're probably going to start off at the ECHL or AHL level anyway so they will still get the NHL looks and instruction that you refer to. Their odds of doing better at the pro level are just better.