The Mandalorian proved that it could keep big secrets going all the way back to Baby Yoda in the first season, but the show really outdid itself in Season 2 by managing to keep Mark Hamill's return as Luke Skywalker from leaking. Of course, it wasn't by pure happenstance that Hamill's appearance went unspoiled, as the team behind the scenes went to great lengths to keep the secret. In fact, they used a Clone Wars character to hide the return of Luke. As far as most people knew before the big reveal, Plo Koon was the Jedi who arrived to save the day for Mando and Co.
The newest episode of Disney+'s Disney Gallery: Star Wars: The Mandalorian revealed just how far the team went to keep the big secret, with Mark Hamill himself pointing out that all it would take is one person and one post on social media for arguably the biggest twist in Mandalorian history to be totally spoiled. Season 2 finale director Peyton Reed explained how Luke Skywalker wasn't spoiled before the episode released:
We had to keep Mark a secret, and that went from creating misleads in the script, creating art work that was not Luke, creating some temporary visual effects that were the character of Plo Koon.
Plo Koon made his Star Wars screen debut with the prequel trilogy, and seemingly died in the Order 66 sequence in Revenge of the Sith, but his death wasn't explicit like it was for some of the other murdered Jedi. Plus, he gained much more prominence as a Jedi thanks to Star Wars: The Clone Wars, where he had some notable arcs and a close relationship to Ahsoka Tano, who made her Mandalorian debut in Season 2. Plo Koon could have worked, so he was a good choice for the fakeout.
Honestly, after Star Wars: Episode IX - The Rise of Skywalker featured Palpatine "somehow" returning on top of other wild moments, Plo Koon's survival wouldn't be the hardest twist to believe. He made sense as a substitute Jedi who would save the day, if The Mandalorian was going to go for somebody more well-known than Star Wars Rebels' Ezra Bridger and Star Wars Jedi: Fallen Order's Cal Kestis. And the art that the Mandalorian team created to sell Plo Koon's reveal was pretty convincing! Take a look:
As it turns out, there's a reason why Plo Koon was a smart choice as the fake Jedi even beyond his arguably ambiguous demise in Revenge of the Sith, and it's all thanks to Dave Filoni. The Mandalorian executive producer was also supervising director on Star Wars: The Clone Wars, and he made no secret of his feelings about that particular Jedi. Filoni explained:
It's fairly well known by deep core fans that Plo Koon’s my favorite Jedi. And a lot of people, if Plo Koon from the script got out, would assume, ‘Well, of course, ‘cause Dave likes Plo Koon.’ So there’s these layers of intrigue that we try to weave. We had a digital Plo Kool head placed on the actor in dailies, so it looked like Plo Koon.
As far as I recall, it was not "spoiled" that Plo Koon would turn up in the Season 2 finale of The Mandalorian, and even the most significant of Plo Koon "leaks" wouldn't have given away the arrival of Mark Hamill's Luke Skywalker by the end of the season. Dave Filoni even kept a former Clone Wars actor who reprised their role for The Mandalorian in the dark, as Bo-Katan star Katee Sackhoff shared earlier this year that she fully believed that Plo Koon was on the way.
Alas for Plo Koon fans, this may mean that the Jedi is truly as dead as he seemed as of Order 66 in Revenge of the Sith, although the Mandalorian team does already have some concept art handy to show could awesome it could look if he returned. Really, one should never entirely rule much of anything out when it comes to Star Wars. If you want to relive the excitement of the build to Mark Hamill's Mandalorian debut, you can find the full run of that series so far streaming on Disney+, along with more of Disney Gallery: Star Wars: The Mandalorian.
