The CEO of a Jewish civil rights and advocacy organization urged Met honchos to cancel the 2027 Gala’s John Galliano theme in a last-ditch crisis meeting, Page Six has exclusively learned. Multiple sources told us Jonathan Greenblatt of the Anti-Defamation League (ADL) had breakfast with Max Hollein, CEO of the Metropolitan Museum of Art, a few weeks ago at the Loews Regency New York hotel. At least one Met board member was also present, we’re told. “[Greenblatt] was urging them to reverse the decision on the Galliano show,” one of our sources said, noting that while the eventual decision was the result of “a combination of things,”…