The Mandalorian season 2 actually teased Grand Admiral Thrawn before the big scene that dropped his name on the show. In a surprising reveal, Thrawn was mentioned by name by Ahsoka Tano (Rosario Dawson) as the superior of Magistrate Morgan Elsbeth (Diana Lee Inosanto). The reference to the established Star Wars character suggested that he could appear as a villain at some point in The Mandalorian’s future.
The Mandalorian season 2, episode 5, “Chapter 13: The Jedi” opened with the live-action debut of Ahsoka Tano, the fan-favorite Jedi from Star Wars: The Clone Wars and Star Wars Rebels. Currently based on the planet Corvus, Ahsoka was single-handedly waging a war on an Empire base being run by Morgan Elsbeth. Shortly after arriving on Corvus, Mando (Pedro Pascal) joined forces with Ahsoka and helped her take down the magistrate’s forces. Following her victory in a heated one-on-one showdown with Morgan, Ahsoka asked her about the whereabouts of her “master”, Grand Admiral Thrawn.
Since Thrawn is a major antagonist in numerous Star Wars novels and Star Wars Rebels season 3, this was a regarded as a major reveal. However, an Easter egg that surfaced earlier in the episode already teased his involvement in the story. The HK-87 assassin droids that accompanied the magistrate had insignias on their helmets that matched the symbol of the Seventh Fleet. In the Star Wars universe, Thrawn is a high-ranking officer in the Galactic Empire chosen to command its Seventh Fleet. Since it seems that Morgan may have been a part of his Seventh Fleet, it makes sense that her resources would consist of remnants of his old forces.
What the reference to Thrawn and the Seventh Fleet Easter egg in The Mandalorian’s Ahsoka Tano episode mean is that both are likely to be important going forward. So far, it seemed that the only big recurring threat in the Disney+ series is Moff Gideon (Giancarlo Esposito), considering that he has sinister plans for Baby Yoda and other schemes that haven’t been fully fleshed out yet. But, it may be that in future episodes Mando will have to deal with two separate factions of enemies. Or, it could be that the two are connected in some way.
If that’s the case, Grand Admiral Thrawn could be the one that’s really pulling the strings. It may be that for now, The Mandalorian will focus on Mando’s fight with Moff Gideon, and then move on to Thrawn in season 3. When Moff Gideon is defeated could be when Thrawn emerges. When that happens, Ahsoka Tano may come back into play. After all, it was never shown what was said after her question to Morgan. It’s not clear if the magistrate held her tongue, or if she spilled her secrets to the Jedi. If Ahsoka does now know Thrawn’s location, she could be around whenever he gets pulled into the story.