I'd like to reiterate - there is no magic formula based on velocity for where your son could end up. If you over-analyze it, you may be taking opportunities away from him that could've worked. I have a younger son who was 5-10 and threw 85 in HS. Had we relied solely on velocity or pitch differentials (combined with size - another measurable)...we would never targeted a Pac12 school...let alone a D1 at all.
Instead, we listened to his coaches and a scout or two and let them tell us he could indeed pitch in that league and so we put him in front of them and he ended up at one.
OTOH, you may see 92 some day and convince yourself your son is an SEC pitcher. Maybe? Maybe not?
You have to take a little risk here - put your son in front of them and see what happens. No, I wouldn't become a 'showcase pitcher' running all over the place, but you can do one or two and see what happens. That will give you the answer.