I assume by your question that the "ideal" school isn't offering?
In D1, you will find very few schools that hold on to scholarships after early signing period. They will often just move on to their next choice.
There are exceptions,for sure!
Some schools will lose scholarship kids at semester break,due to many factors, including being cut or told that they won't play the next year. That would then free up $$ for the Spring period.
The draft could be a factor, but often it isn't until August until they know if a drafted kid will sign with a MLB team.
A lot of kids will sign early with a viable JUCO program, which still allows them to be 'free agents', so to speak, for D1 or D2 schools in the Spring. And, if those don't come, he still has the opportunity after his Freshman or Soph year to move on to a 4 year school.
It's a "roll of the dice" to wait, but sometimes it can be worth it!
Best of Luck!