All schools signed off on the amendment. It was announced Maryland and Florida St weren't initially in support but ultimately every school signed the agreement. Maryland doesn't have much of a case, they are just trying to see if they can whittle down the exit fee.
I still contend the B1G will step in and ease the burden on the Terps. They can easily pay the fee in full and deduct it from future B1G revenue for the Terps from both the main contract and B1G network.
Do you have a source that says Maryland ever signed off on the increased exit fee? I know Florida State did when they agreed to the Grant of Rights, but it was my understanding that Maryland never explicitly agreed to the exit fee increase. It was always my understanding that the reason they are bound by the increased exit fee is because as members of the ACC they agree to be bound by ACC by-laws, and the exit fee was an amendment to the conference by-laws.