I am not certain what they would gain from it. Is it worth it to the family to drag out the litigation process 2 more years for 4 million? The stress and continued attacks with the possibility of losing. I wouldn't do it.
Maybe their lawyers told them that they didn't have much of a choice. Or maybe they are trying to play fair. Maybe the family is hoping for a favorable relationship with Oberlin in the future and so that they can reestablish the business relationship with the college.
Oberlin has the legal right to appeal, which takes roughly two years.