I'd say something like 75% to 85% of the players drafted each year don't get calls or meetings with scouts. So, if you son is in that group, there's no reason to think "he probably won't get drafted" when he's filling out, signing and returning forms from teams or like the attached.
Hopefully, your son won't get too stressed out about it. If and when your son's name is called, savor the experience. 