Okay, well, I'm not seeing DI games on a regular basis, so I can't argue with you. All I'm saying is the DI RHP commits on the 17U team my son pitched for a few times in his program all threw mid to upper 80s touching 90 and I saw that with my own eyes at PG WWBA 17U tourney.
Before the "crickets" I would have agreed with you 100%. My kid is probably the top starting pitcher on the 16U team (now 17U for the fall), and couldn't get on the 17U team staff because they were loaded with mid to upper 80s guys. Kids that are committed on 16U are younger (2023s) throw low to mid 80s or are 2022 lefties low to mid 80s. Power 5 and lower DI commits. Son is a young 2021.
Honestly, I'm at a loss not about DI, but about DIII interest or apparent lack thereof.
In the "old days" (i.e. last year), the schedule was that D3 players with first-wave offers of admissions support would be visiting throughout September, and as they decided where to "commit" (i.e. apply Early Decision), the boards would shuffle. My son was told by coaches that they wanted his decision by the end of September. This year, I have no idea what the timing is. Coaches may not know either, other than the ED deadlines are still in early November. What does the travel coach say about the D3 recruiting timeline this year?
I agree with what Cabbagedad says to do. In a few weeks, take more video of him pitching (in a bullpen), with a radar gun, and send it with an email reiterating his interest. Which camp did he attend? If he's already been to Headfirst or Showball, it's hard to know if there is a point going to another one - they will have the video from the first.
Many good D3 colleges recruit all through senior year; if there are schools where he doesn't need coach support to get in, look at those. Many will give hefty academic scholarship money, unlike the more selective ones. Send email with fresh video. Go to early spring camps if they have them.