For those who have sons heading to a D3 college as a freshman, I think the path can be quite different.
As Hokieone noted, D3 kids can play and a number of leagues and teams are now more aware than ever. However, a D3 college coaching staff has trouble convincing a GM to take a freshman during the Fall, when the D3 player has nothing successful at the college level which can be provided to the Summer league team other than the coaches word and reputation. Our experience is that D3 college coaches who want their freshman to play at the better leagues will wait until the Spring, let them put up some numbers and then put out placement options through reliable contacts. It is not ideal for the player or parent, but it works.