I don’t know many schools willing to bother finding out whether the use was fair.

It is not the school’s responsibility to bother finding out. It is Disney’s responsibility, as the troll claiming copyright protections, to make the claim that it’s not fair use, and it is the court’s responsibility to determine the validity of such a claim.

Unless Disney decides to intervene, there is no question that it is fair use. Even if a copyright troll does decide to intervene, it is still probably fair use.