I don’t think so, but these schools will be looking to be done by the start of the summer - if they can.
I think it’s the best you’ve got, but not necessarily accurate. There are plenty of swimmers (athletes in general) who prefer to keep their cards close. This is particularly true of Ivies, where kids are simply committing to the process and academic D3s where it’s ultimately up to admissions. I don’t know if you noticed but many commitments have showed up for 23s in the last week, as acceptances have come out. It’s impossible to say when offers were made and accepted.
Top recruits already visited in the fall. I think there are plenty of top mid-major coaches who are waiting to see what some target recruits will do this coming season (late March championship/ many coaches will attend Sectionals). There is a lot of growing that happens at this age, particularly on the boys side. There will be OV weekends in the Spring.
I don’t know if this is a D3 or NESCAC rule. I think D3? I don’t believe it applies to Ivies. Regardless, coaches have a pretty good pulse on what it takes to pass a pre-read and Ivy coaches have a lot more academic wiggle room.