1. Plo Koon

To keep people off the scent of this big reveal, the episode’s script had it written that beloved Clone Wars and prequel Jedi Plo Koon arrived to retrieve Grogu. On set, even when Mark Hamill himself was standing there, they called him “Plo Koon.” Fake concept art and digital effects (as seen above) were created in case there was a leak as well. The team felt, since Plo Koon is known to be executive producer Dave Filoni’s favorite Jedi, it was a plausible misdirect.
Oh, and as the date of the episode got closer, Lucasfilm employees would scour sites like this to see if anyone had put together the pieces yet. No one had.