Well, I don't see anything in the CBA that specifically covers Jack LaFontaine's circumstance, where a player leaves college, plays somewhere else but retains eligibility, and then comes back. In fact, I would be more inclined to disagree with Matt Somma.
All of this info is being pulled from the nhlpa.com CBA linked here:
https://nhlpa.com/the-pa/cba
The CBA defines 'graduating class' as:
For purposes of the above provisions, the term "graduation of his college
class" shall mean the class with which the Player is scheduled to graduate
during his final semester of attendance (as opposed to his matriculating
class (the class with which he is expected to graduate as of the date of his
original enrollment)). For purposes of clarity, a Player's graduating class
may change during his tenure in college.
As far as the NCAA in concerned, Jack Lafontaine is a junior. That means his graduating class would not graduate until next year. That being the case, we would hold his exclusive negotiating rights until August 15 of 2021. There is another clause that covers situations where kids are no longer bonafide college students, but that doesn't cover anything having to do with what happens if they become a college student again. If that clause is applicable, that would lead to the deadline being the 4th June 1st after the draft given LaFontaine's circumstances (aka the coming June 1st). I don't see anything in the CBA document that would lead me to an August 15th 2020 deadline for signing LaFontaine. I read the CBA as the date being August 15, 2021. But all I have is the CBA document, Matt Somma might have confirmed the reality with someone else. Certainly the original CBA has no clause that specifically covers a kid being a college student, leaving college, and then going back to college.
I will note finally though that the CBA says this at the end of the exclusive rights college section:
As a general matter, the above provisions were not intended to cut off, and
shall not have the effect of cutting off, a Club's exclusive negotiating
rights during the period that a Player remains in college.
Given LaFontaine's situation, I take that clause to mean that LaFontaine and the Canes should not be in a situation where LaFontaine has to choose between signing with the Canes or staying at Minnesota for his senior year with the Canes losing his negotiating rights. That is how I read the CBA, I could of course be completely incorrect or the CBA could have been modified or clarified.
Rizzo and Kucharski and Cade Webber I believe are a bit easier. They should fall under the basic college student clause:
If a Player drafted at age 18 or 19 is a bona fide college student at the time
of his selection in the Entry Draft, or becomes a bona fide college student
prior to the first June 1 following his selection in the Entry Draft, and
remains a bona fide college student through the graduation of his college
class, his drafting Club shall retain the exclusive right of negotiation for
his services through and including the August 15 following the graduation
of his college class. The Club need not make a Bona Fide Offer to such
Player to retain such rights.
Kucharski actually left the USHL early last season and enrolled in Providence for the Spring semester. Rizzo is heading to the University of North Dakota after this season. Cade Webber is going to Boston University under the same circumstances. Now I suppose one could ask 'when do these players actually become bona fide college students and does that really happen before June 1st'? Of course the CBA never defines at what point a player becomes a bona fide college student. But Rizzo and Webber were committed to their college teams for next season before the BCHL season even began. Kucharski was attending classes at Providence last spring. So to me they all fall under that basic 8.6.c.i clause as long as they remain college students.