On Sept 1st there will 100% be a flood of commits. These coaches have been biting at the bit to commit their 2019 class. They want it done and over so they can concentrate on the next recruiting class for 2020. The coaches are also very busy at this moment with the incoming 2017 freshmen and getting their house in order. They want to lock up their kids now because if there are a few declines they need to get on to the next kid on their depth chart. Many of the studs who did not commit early and and or had their commitments put on hold are also biting at the bit. These players and their families also want it over with.
I am sure there will be a lot of conversation on Sept 1. but how fast that translates into commits, I am not too certain about. I think it would be wrong of a coach to give a player less than a one week turn around. Many haven't had the opportunity to speak with any coaches.
I also don't believe all 2019 will be locked up by year's end; like the 2018's there were some pretty good players picked up this summer. Maybe the top 10 schools will be 95% by Thanksgiving, but those schools outside the top 30, I don't think so.