It's already been unsuccessfully challenged in the past.

Are there new circumstances that would cause the courts to take a fresh look at this?

From Mike Williams' wiki page:

"Ohio State running back Maurice Clarett was suspended by his school following his 2002 freshman year. After being unable to gain reinstatement with Ohio State, Clarett made the decision to declare for the NFL Draft. However, since Clarett was only of true sophomore eligibility, he had to legally challenge the NFL rule that a player must be three years removed from high school to be eligible for the NFL Draft. After a court proceeding, a federal judge ruled that the NFL could not legally bar Clarett from entering the 2004 NFL Draft.

Williams, having completed his sophomore year and only two years removed from high school, made the decision to declare for the 2004 NFL Draft as well after hearing the federal judge's ruling. Williams hired an agent and moved forward presenting himself as a legitimate first round pick (and most, if not all, NFL pundits and NFL personnel agreed that Williams was a first round choice). By declaring his intent to enter the draft, hiring an agent to represent his interests, and filing the NFL paperwork necessary to enter the draft, he made himself ineligible for NCAA reinstatement.

Still, prior to the 2004 NFL Draft the United States Court of Appeals for the Second Circuit overturned the Federal Judge's decision allowing Clarett to enter the Draft. Additionally, the United States Supreme Court refused to hear a final appeal. Clarett and Williams were ineligible for the 2004 NFL Draft.

As Williams was ineligible for NCAA reinstatement, he was required to sit the entire 2004 football season and was not allowed to practice with USC as well."

Click here for link at https://en.wikipedia.org/wiki/Mike_Williams_(wide_receiver,_