It doesn’t matter when they made the arbitrary cut off date because the rule would always affect one class and with the current state of football that means players from that class would have found a lawyer and sued in a local court. I understand one argument is that maybe these guys would have just stayed in college had the 5 for 5 rule been instituted at a different date, but I don’t buy it. I’m positive there would still be guys who would have went pro, not made a roster, then would have sued for that fifth year.
I’m sorry these guys went through nfl training camp and didn’t make a roster, but that does not mean they should get to return to CFB.
That said, the most insane part of this is the judge saying the SEC can’t punish member institutions. Ruling players can return is one thing, and maybe, as your post states, there’s even a small argument for it. There is not, however, an argument for saying that conference can’t make and enforce rules, which where voted on by conference members. Conference members who joined the SEC of their own free will and agreed to abide by the conference rules.