Confirming the second high-profile cancellation in as many days, the Metropolitan Opera said that, for “personal reasons,” the mercurial soprano has pulled out of six of her eight scheduled appearances as Carmen, including the New Year’s Eve gala and a worldwide high-def simulcast. “The production was conceived as a showcase for Ms. Gheorghiu and her husband, the tenor Roberto Alagna, who will still be singing Don José. It happens that the six performances Ms. Gheorghiu will miss are those in which Mr. Alagna was to have been her co-star.”