Ainge isn't going to renegotiate. He's going to have the deal rescind and leave the Cavs with nothing, especially losing that draft pick. What's more than likely going to happen is that IT is going to be on injured reserve, have the operation done for his hip, and then be traded mid-season for low value. Rumor has it now, that Ainge is in talks with Golden State for Klay Thomspon. Either way, Ainge is going to acquire someone and STILL have the leverage and the picks to get someone if he cannot get Kyrie.
Meanwhile, the Cavs is going to be stuck with Kyrie and more than likely not going to trade him. If they DO trade him it's not going to be as great of a deal they had with the Celtics. People saying this is to the Cavs advantage, I don't see it. That's assuming that Ainge REALLY want Kyrie that bad instead of him really want to get rid of IT.