Our coaches evaluate signability constantly. They do this by talking to the player, his family, the high school coach sometimes, and scouts. We do that for every player so that we have a good idea what to expect. Heck, I know Cohen told Dan that Cord Sandberg was going pro.
It's just part of doing business in baseball, and everyone has to deal with it- especially SEC teams. But I would be very shocked if our coaches were surprised by Burdick. Normally once a player is drafted, they contact that player as soon as possible.
Believe it or not, it goes both ways because MLB has lost some players to college because the player has leverage and even though MLB wins most of the time, they still have to compete with college and MLB doesn't like that.
But three months is plenty of time to replace a guy. Or the coaches can choose to bank the scholarship money for another high end guy in the next class. Cohen and his staff are all the time scouting and sign players in the spring in part because of the draft- they know that they might lose some people out of high school and they need to be able to replace them as seamlessly as possible.