[Lorne] Michaels noted one small adjustment made for Mr. Williams’s sake. A planned sketch about edited-out parts of the Harry Potter films featuring the recently outed Dumbledore will not star Mr. Williams as Dumbledore. And the show will surround Mr. Williams with high-quality support, including two big-name surprise guests, one from politics and the other from music.We also know from the promos that Bronx Beat will be back and that Feist is the musical guest. 11:30 p.m. Saturday. NBC.