EJ Panaligan editorIFC variety comedy series “Sherman’s Showcase” is returning for a second season on the network along with AMC+ on October 26, and the full guest lineup has been announced, headlined by EGOT winner and series executive producer John Legend and “Insecure” and “Rap Sh!t” creator Issa Rae. IFC announced the news on Wednesday during AMC Networks’ day at the TV Critics Assn.