Star Wars has revealed Moff Gideon's status, following the major battle that took place in The Mandalorian Season 2 finale. Gideon was leading his own battalion of Imperial Remnants and engaged in all kinds of unholy experiments on the side – some of which could be tied to key story points and character arcs from the Star Wars Sequel Trilogy films. Obviously, since Mando didn't kill Moff Gideon in their duel, the villain is still lurking around with the potential to cause trouble: so what has he been up to? Thanks to The Book of Boba Fett, we know have that answer!
(WARNING: The Book of Boba Fett Chapter 5 SPOILERS Follow!)
The Book of Boba Fett Chapter 5 is actually a side-story, which catches us up with "Mando" himself, Din Djarin. The episode essentially functions as a setup for The Mandalorian Season 3 (as well as a thematic bridge to Boba Fett), and one item on the checklist is Din Djarin having to reconnect with his clan of Mandalorians, led by the Armorer.
Moff Gideon had a hand in the Great Purge of Mandalore and became the holder of the Darksaber, one of Mandalorians' most prized weapons. That's all to say when Din Djarin returns to his clan (what's left of them) with the Darksaber in hand, They have questions that need answering!
Mando reveals that Moff Gideon is still alive, and has been "sent to the New Republic for interrogation. And he will face justice for his crimes." Fellow Mandalorian Paz Vizla chides Din Djarin by saying death was the true justice for Moff Gideon, with the Armorer adding that the Imperial commander has "the blood of millions of our kind on his hands."
In that context, Mando feels confident that Moff Gideon will be "executed by the New Republic tribunal for his crimes," but the Armorer isn't so sure about that...
The Mandalorian Season 2 made a lot of Easter egg references to Moff Gideon being a key figure in helping Emperor Palpatine cheat death through cloning, and create his "Snoke" puppet persona. In that sense, Moff Gideon could easily get a jailbreak, or never make it to a cell in the first place. Palpatine's machinations are already at work in this New Republic era, so getting back one of the few men to know the secret of his survival (and Sith Empire plans) seems like it wouldn't be too hard.
Star Wars: The Mandalorian Season 3 is expected to arrive sometime in 2022.