Scared, but not in the sense of peeing the bed.
Scared because they believed that if the Terps won, the conference would likely fall apart. The ACC did not “lose”, but it is difficult to call their deal with Maryland a “win”. They maintained the $31 million they had withheld from Maryland and allowed the Terps to settle. They sued MD for $52 million. MD agreed to pay $17 million. The settlement was barely shy of the middle ($34.5 million).
I’m not predicting a similar outcome, but if FSU prevails today, the ACC is well aware (rather than just a theoretical “chance” as in 2013/14) that the conference will implode instantly. Every school with the opportunity to move to the B1G, SEC, or Big 12 will depart.
I’m making no predictions about any of this. However, if FSU files the case in an attempt to overturn the GoR, the ACC will have to “bet the farm” on the outcome. If an adverse ruling is issued, the entire conference will be canceled. These are extremely high litigation stakes.