I understand they fear their death coming, but this would delay it no?
I'm not sure what you are asking . The reason they are getting money isn't because they sell ads (they don't), its because the amount of people viewing the Show allow USA to be the number 1 cable network on Average on a year-long basis (If WWE wasn't on, they would probably fall to Disney). So broadcasting the show on the Network, ads intact, does nothing for USA.
If WWE wanted to break the contract with USA, which is paying over 200 million dollars guaranteed a year for a unknown amount of years, they would need to add something like 1.7 million subscribers per month (and that's assuming 0% of the money goes to MLB.tv who powers the network) to get the same amount of money. And they would need to maintain that, because if people cancel, they would be fucked