For a 2020, next Summer is the prime time for HA D3 and some HA D1 recruitment. Averaging 83 now, and touching 87, puts your son in the discussion at both levels as a 2020.
As others have noted, he has time for development/improvement. Given his desired college focus on HA schools (very few verbal commitments yet at most HA D1), he should focus on improvement of velocity and command now. Average velocity continues to rise across baseball. And it can be improved.
Also, as has been noted, casting a very wide net at this stage is a great idea. Lots of schools could fit...hard to say where at this point.
Having been to this rodeo a couple times, I'd look at camps/showcases beginning later this Fall and into the Winter to begin testing the waters again after more development. Places like Headfirst Jupiter and Winter camps at places like Harvard or Northeastern. Continue to work a plan of engagement with coaches (and potentially admissions reps) of the schools on his vetted list, e.g., campus visits, send video and emails, etc. through next Spring. The time to really shine will be Summer 2019.
Good luck!