It’s interesting that the Disney Gallery special had no clips of Mark Hamill or anything related to Luke’s appearance, so it seems that they really did everything they could to avoid any leaks for the finale. Makes me wonder if they did something similar to ESB were the script that most people got had a different scene, and I’m guessing that they had a very small crew shooting that scene. They might not even have had the entire cast, so it wouldn’t surprise me if some of the actors didn’t even know who they were supposed to react to.