2017 son also attended in 2016 as dual player-C/RHP and he got a chance to do both in games catching the first day and pitching the next. The talent level was better than what we saw at most showcases. Tons of great players in the SD and south Orange County areas attended, and we definitely saw future MLB draftees there.
There were coaches at all divisions in attendance at both the skills test and at games, but they tended to be very low key and kept to themselves with their guns and notepads (unlike the showcases where they participate). So it is possible your son may not see or talk to any of them, but rest assured they are there. They go where the talent is, and it was there, so if your son is talking to any of the area school coaches be sure he lets the coaches know his schedule. It is also a great place for your son to assess how they stand against the competition.
Ironically, this was the first time my son heard from a coach at the university he eventually wound up at, so we will always hold this PG event as a very fond memory.