They did in my son's case. He went to a couple showcases over the winter where he was seen and received calls afterwards. But it wouldn't be a bad idea to let them know of his interest if there are particular ones he might like. I have seen on some of the websites where there is actually a form that can be submitted over the web, but I think personal contact might be better.
The jucos and NAIA schools have a whole lot more flexibility in their rules than NCAA schools. My son actually went on one visit where he was able to workout indoors with the team in their offseason and throw with one of their catchers in the pen. It was a great way to meet the players and get a feel for the coaches interaction with their team, without the formal setting of a 'camp'.