5 years ago if you went to a D1 school and weren't getting a crack, you were replaced by a high schooler who had to deal with the same learning curve you did. Now you get replaced by someone who already hit .380 with 16 home runs at the collegiate level.
I think it works out better for HS players. Before, schools took everyone and said goodbye to those who couldn't hang. Not that it doesn't happen anymore, but there are less mistakes happening out of HS. Once you're on campus you're more easily replaceable than ever.
Long story short - Good for HS players. Bad for rostered players. Everybody has been pushed down a level. The biggest winners have been D2/D3 baseball who now have players who would have probably found themselves on a D1 roster 4 years ago.