Given the JVs that DL has it could be any combination from switching you to another AF/DL flight ex JFK to CDG that day or to a DL/VS to LHR then AF to CDG or a DL/KL flight to AMS then KL/AF to CDG

They will move heaven and earth to re route you on to a JV flight. They will only book you onto another out of JV / ST airline in extremis