The Met Gala hasn’t always been a capital-E Event. The invitation-only gala, which benefits The Metropolitan Museum of Art’s Costume Institute, began in 1948 as a fundraiser that marked the Institute’s annual spring fashion exhibition and was attended primarily by high-society museum patrons. In the 1970s, the celebrity friendships and pop-culture savvy of former Vogue editor Diana Vreeland brought fashion-party glitz to the previously staid dinner; starting in 1995, Anna Wintour’s meticulously curated guest lists established it as a gauge of pop-culture relevance whose attendees — actors, athletes, artists and politicians — defined the zeitgeist. Since then, the Gala itself has become a staple of pop culture, with celebrity co-chairs and a host committee stacked with luminaries, a global viewership that grows exponentially year over year, and a seating chart that has accrued its own body of lore. It also, increasingly, is a site of heavily anticipated controversy and social-media chatter about attendees fumbling the theme, making political statements and occasionally committing cultural sacrilege. This year’s controversy began when Jeff Bezos and Lauren Sanchez-Bezos were …