I do believe that many JUCOs have a rather large presence at Jupiter. Although my son had verbally committed way before Jupiter to a D-1, after playing in Jupiter he started getting contacts from JUCOs in the South. The closer to the draft, the more contacts.
Realize that a lot of kids who are potential draft picks next spring are now going to get on the radar screens of top notch JUCOs. Some kid who doesn't like his draft position or $$$ offer can attend a JUCO and be eligible for the draft the spring following his freshman year. (D-1 kid not eligible until after junior year)
Schools like San Jacinto CC probably end up with a better pitching staff than most D-1 schools. I would guess that half of their top recruits probably do not even committ until after the draft. I saw a lot of those top-level JUCOs in Jupiter too.