Star Wars: The Bad Batch season 1 seems to be setting up a Legends-accurate Thrawn story in The Mandalorian era. Star Wars has always been fascinated by clones, ever since a throwaway reference to the "Clone Wars" in the first movie. For some time George Lucas was reluctant to explain what these were, and it fell to writers in the old Expanded Universe to explore cloning.
Now, at last, the full story of the Clone Wars has been told. The Clone Wars were the ultimate Jedi trap, with the Jedi fighting at the forefront of an army of clone troopers created by the Kaminoans. They came to a climax in Order 66, with the clones turning on the Jedi at Palpatine's command, slaughtering all those who had not already died during the conflict. And the age of clones seemed to come to an end some months later, with the destruction of Kamino shown in Star Wars: The Bad Batch season 1's finale. But, curiously, that episode contained one final scene that seemed to hint at a future clone plot lifted straight from the old Legends stories.
The Star Wars: The Bad Batch finale ended with the Empire transporting Nala Se, the Chief Medical Scientist who ran the clone program, to an Imperial facility on an unknown planet. Given the uniforms worn by the scientists at this base, it's reasonable to assume this will be where cloners seen in The Mandalorian era were trained - notably including Dr. Pershing, who was responsible for experiments on Baby Yoda and appears to have been working with the Chiss Grand Admiral Thrawn. Concept art confirms this is Mount Tantiss on the planet "Weyland," which appeared in Timothy Zahn's (now non-canon) "Thrawn trilogy."
In the old Expanded Universe, Mount Tantiss was found on the Outer Rim planet Wayland. It was one of the Emperor's treasure-houses, and among other things it contained sophisticated cloning facilities. The Disney era has built upon this idea, revealing the Emperor established countless of these across the galaxy - including an Unknown Regions Observatory on Jakku - and the Vader Immortal VR game has already confirmed one of them was based on Wayland in canon too. It's therefore quite possible this mysterious mountain is an Easter egg, and Nala Se has been taken to an Imperial stronghold on Wayland. Previous episodes of Star Wars: The Bad Batch established that bases built into mountains like this are resistant to scanning, thus difficult to spot from orbit.
This may well be setup for a Legends-accurate Thrawn story in The Mandalorian's time-period. Delighted by the success of The Mandalorian, Lucasfilm is increasing the number of shows set in this time-period, and they've set up Grand Admiral Thrawn to be very important; he appears to be responsible for an Imperial resurgence in the Outer Rim. Significantly, he's even operating around Wayland, and he appears to be tied to Imperial Clone Engineers such as Dr. Pershing. All the pieces seem to be falling into place for Star Wars to tell a remarkably Legends-accurate Thrawn story in The Mandalorian and its surrounding shows.
Star Wars: The Bad Batch will return for season 2 on Disney+.
