crossbill,
It's not too late, my 2013 was behind 5-6 sr. pitchers last season, and a few of those were D1 pitchers so he did not get a lot of time. He was concerned but kept working in the classroom and conditioning. He as played this fall and went to a few showcases.
What we found out was that in the fall when these colleges start going through their fall program they assess what they have coming back and coming in. Some palyers did not come back to school, some did not have the grades some were hurt.
In the last month my son has had some very good interest from a mid-level D1 a D2 a JUCO a D3 and a couple of NAIA schools. Last season he had a teammate that signed in May at a D1 school.
Keep contacting schools and see if they have a need for players at your sons position. Another thing we learned, college coaches are recruiting on need.
I would not concern myself with the schools that were interested and now are not, but rather the schools that are interested. If he loves the school and wants to walk on , great take your shot. If he wants to play quickly, go to a school that you can play quickly, often not a D1.
I also found that JUCO's take kids in June and July after your sr. season.
Lastly, grades do matter, at first the coaches calling 2013 were not talking about grades, but as they get more interested, the talk of grades always comes up. Just our exp. for what it's worth.