Yes, but if FSU joined the Big 12 for example, the media rights of all FSU conference road games would be held by the Big 12 since they are also home conference games. Networks pay for match ups and FSU as an opponent would be more valuable than say Iowa State. (Also, it is not clear what happens with bowl game TV revenues or playoff revenues as we haven't read the contracts.) Thus, it is possible that even if a school with a GORs joined a new conference (especially if that school is in the ACC with an ~$20 million conference revenue model), they might actually see an increase in conference revenues from TV revenues, bowl games, playoffs,... We'll see what the Big 10 gets when their media rights come up as it is possible that they will be making > 2x the ACC.
I think the key issue is that all contracts have outs and the key to breaching contracts are damages. For example, I don't think Maryland will pay anywhere close to $50 million for leaving the ACC as the ACC has replaced Maryland with Louisville and negotiated a better TV contract for more money. Where are the damages?