Callbacks to past Star Wars films has become one of The Mandalorian's signature trademarks, and the Season 2 finale "The Rescue" packed in quite a few amid its awesome action sets and that shocking cameo.
In addition to Luke Skywalker's hallway scene mirroring that of Darth Vader's in Rogue One, the appearance of Bo-Katan's ship from The Clone Wars, and the use of the phrase "Maclunkey!," eagle-eyed fans spotted a fitting tribute to C-3PO (after all, his counterpart R2-D2 did make an appearance in the finale).
As a user noted on Reddit, the silver RA-7 droid seen in The Mandalorian's Season 2 finale episode was sporting a gold leg. This design choice was surely intentional on the part of the production team, as it is a nod to how golden droid C-3PO sports a silver leg.
It's hard to imagine that this design decision wasn't intentional, especially since R2-D2 appeared alongside Luke Skywalker. Besides, Favreau and Filoni seem to love peppering their episodes with these Star Wars Easter Eggs, references, and even foreshadowing, but they're executed to be in service to the story.
WHAT THIS MEANS
So far, The Mandalorian has been a masterclass in demonstrating how fan service can and should be utilized. But the question is, now that we've seen R2-D2, could we see C-3PO appear in the future?
Since Ahsoka had her doubts about training Grogu, and since we didn't hear about Grogu in the Sequel Trilogy, it seems doubtful that audiences have seen the last of the internet's most popular obsession. So if we see Grogu again, it's possible we might see Luke in some form or fashion; and if so, possibly Threepio alongside R2? Only time will tell.
After all, legendary C-3PO actor Anthony Daniels reprised his role for this year's The Lego Star Wars Holiday Special on Disney+. And after seeing a young Luke Skywalker interact with Mando and Grogu, anything could happen in future seasons of The Mandalorian.