That system stinks for a kid who actually plays in the NCAA Championship game. He's got 10 days to accumulate information and make a decision, whereas a guy whose team lost in the first round has twice that time. I assume coaches spend more than ten days making calls for their players with various NBA contacts, so coaches would have to be making calls for guys while simultaneously preparing for NCAA games, which is to say these calls probably would not get made. There are many guys whose stock rises or falls siginificantly enough in pre-draft workouts too.
Overall, I think it's a poor idea.