When you say HA D1s I assume you mean Patriot, Ivy, some of the Colonial, etc. Because Duke, Vandy, UNC, and Stanford are all HA as well and none of them are too concerned about the Sept 1 date.
I would say that unless your kid is a can't miss prospect for them (P5/high level mid major caliber) most of the more serious conversations will take place next summer. A lot of these schools don't have much if any money to play around with and want to make sure you are essentially a done deal before they offer. They also need to make sure grades and test scores are there before moving forward. Most don't take it until middle or end of Jr year. Unless he's receiving phone calls/texts/personalized emails don't worry about it too much.