Unlike FSU, the ACC got the vote before filing. From the ACC's suit in Charlotte against Clemson:
"On March 20, 2024, the ACC held a special meeting in which three-fourths of the ACC’s member institutions waived the three-days’ notice requirement under Section 1.5.1.5.1 of the ACC Constitution, and in which more than two-thirds of the ACC’s member institutions voted to approve the filing of this Complaint."
Of course, it does not identify which members approved.