During his monologue, John Goodman says it's his thirteenth time hosting. It is in fact his twelfth. His first time hosting was thirteen years earlier, in John Goodman/k.d. lang (1989) and he only missed out on hosting during one season, the 26th.
During Weekend Update, Tina Fey makes a joke about Michael Jackson and says "I told you we'd be back, Michael" but it was Jimmy Fallon who had made this promise a few minutes earlier.