For the monologue of his second stint as a guest host of “ Saturday Night Live ,” actor Miles Teller told an endearing anecdote. As children, he and his sisters would dress up as iconic characters from the show for Halloween. (Teller offered visual evidence of the trio dressed as the Roxbury Guys.) The story, which he recounted during the Nov. 1 broadcast, was sweet, but also raised a pointed question: Which creations from the show’s current season, one dominated by high-profile departures and