Yes in short is the answer to your question. If the seller and buyer have agreed to include Incoterms then this will essentially define the risks and responsibilities i.e. obligations. Be aware that there are 11 Incoterms that can be incorporated into a contract which can deal with issues like who pays the costs of carriage and who bears the risk and when the risk passes. So yes the obligations would cease in accordance with the Incoterms.