Yes, a task order is a type of contract. Task orders are essentially "mini contracts" that are governed by the terms and conditions of the parent IDIQ. If the IDIQ had been competitively awarded, there could be an issue of prejudice to other offerors by restricting competition with the PoP extension. However, that's not the case here. If both parties agreed to extend the PoP, I don't see a problem. I recommend that you consult with your activity's legal counsel for concurrence.