Sitting on a bench in Central Park on a recent summer day, Fabrice Morvan, the surviving member of Milli Vanilli, was contemplating his future. “There’s ‘Monsters,’ ” Morvan went on, referring to the recent Netflix drama about the Menendez brothers, which featured the Milli Vanilli hits “Girl You Know It’s True” and “Blame It on the Rain.” “Thanks to ‘Monsters,’ those songs, among others, went to the top of the charts again worldwide.” Milli Vanilli’s Grammy was revoked. “We went from being kings to being laughingstocks,” Morvan said, crossing his legs on the bench to reveal socks with a “Star Wars” motif, worn with black Vans.