I'm not sure how. If the ACC contract is not "executed" it can't have any effect, let alone be retroactive.
I agree with you, but the words within the contract state, "executed on September 7, 2012, effective as of July 1, 2012". That implies that the contract was effective before it was executed.
The words on Page 2, part 1 are interesting as well. It states that "each of the Member Institutions hereby (a) irrevocably grants to the Conference during the Term (as defined below) all rights (the "Rights") necessary for the Conference to perform the contractual obligations of the Conference expressly set forth in the Telecast Rights Agreement, regardless of whether such Member Institution remains a member of the Conference during the entirety of the Term and (b) agrees to satisfy and perform all contractual obligations of a Member Institution that are expressly set forth in the Telecast Rights Agreement". Without having access to the defined "Rights" (although we understand them to be First and Second tier rights minus 1 football and 4 basketball games) and the "Telecast Rights Agreement" it is hard to fully weigh in on this GOR agreement. To paraphrase, the GOR agreement states that the Member Institutions "Rights" are bound to the conference for contractual obligations within the "Telecast Rights Agreement".
I see a few options here for movement from one conference to another.
1. If a school leaving a GOR conference is replaced by another school that meets the requirements of the "Telecast Rights Agreement", the departing school would have grounds to argue that the GOR is in place to ensure the "Telecast Rights Agreement" and that the departing school's "Rights" are required to meet the contractual obligations and therefore the "Rights" of the departing school should be forefitted by the Conference because the new replacement school's "Rights" will fill that void. The catch is that the "Telecast Rights Agreement" may be as simple as requiring "X" amount of teams, or as detailed as requiring specific teams and specific match ups.
2. As stated, the GOR is in place to protect the contractual obligations of the Telecast Rights Agreement. This leaves the possibility that FOX or ESPN would be willing to negotiate with a school for its departure to another conference. FOX or ESPN may see it equally or more profitable if a few teams moved from one conference to another. For example, FOX may see more value in total inventory if it allowed Kansas to move to the B1G with Uconn as the 16th School, and replacing Kansas with UofH or Cincy.
3. A school could choose to leave the conference and challenge the GOR in court. The departing school would be able to challenge the GOR, Telecast Rights Agreement, or define Rights. With three or more documents to challenge in court, a departing school would have much more opportunity to look for termination clauses and loop holes.
In summary, I do not believe the GOR forces a school to stay in a conference, but rather is in place to protect contractual obligations to FOX or ESPN. For this reason, I believe any school that wishes to switch to another conference will do so and will find a way to move its media rights with it. But, I also feel that no school currently in a P5 conference is actively looking to switch conferences or they would not have recently signed a GOR.