The unfortunate truth about recruiting is that there's often a huge gap in the perception of parents regarding their son's production at showcases & tournaments and what college coaches evaluate in a kid. In the most polite way I can put it, going off at a showcase doesn't mean squat if you don't fit what the coaches are looking for. That is not to say your son is not a talented player worthy of playing Division 1 Baseball, but the emotional lens parents see their kids through makes objectivity nearly impossible.
On the flip side, showcases where coaches are paid to attend always have at least a minor buyer beware as just because a coach is physically present doesn't mean they are mentally present.
There's a confounding variable here all of us don't know because the way you described how everything played out shouldn't end up with your son getting zero feedback.
A couple of points to address from other comments:
-All High Academic schools are recruiting the 2019 class right now. Period. Do not believe otherwise. Many Ivies have multiple commits on the board already.
-Patience is critical in the recruiting process but if a school is truly interested, they will 100% contact you and let their interest be known.