Thanks to Ahsoka, 16 planets in the known galaxy (and beyond) have been identified as crucial worlds for the future of the Star Wars franchise. As seen in the credits of the new show, the names of several different worlds can be translated from ancient Star Wars text, confirmed to be part of the migration routes belonging to the intergalactic star whales known as purrgil. This signifies their key importance in the ancient past and likely the near future.
In the established Star Wars canon, the purrgil and their migration routes were used by early space farers to safely map out the known galaxy. It's now been confirmed that these worlds were first discovered by early civilizations such as the Nightsisters and Zeffo long before the First Jedi. As such, these planets could have major roles in the upcoming "Dawn of the Jedi" movie from director James Mangold set 25,000 years before the prequels. Additionally, if extragalactic adventures continue these worlds are perhaps known by other galaxies' civilizations who may have also used the purgill. Here are all 16 planets from Ahsoka's credits and their histories.
Your browser does not support the video tag. 16 Arcana 
The planet Arcana was the world containing an ancient stronghold belonging to the Force witches known as the Nightsisters. This was where Ahsoka Tano first found the star map leading to Grand Admiral Thrawn and his extragalactic exile as seen in Ahsoka's premiere. It's also where Ahsoka fought the HK assassin droids sent by the Nightsister Morgan Elsbeth to retrieve the map. Considering the world's connection to the ancient origins of the Nightsisters, it follows that the world is part of the purrgil migration routes as the Nightsisters used the whales to relocate to the known Star Wars galaxy from their original homeworld of Peridea.
15 Ierne 
There is very little known about the new planet identified as Ierne in Ahsoka's credits sequence. Other than being part of the purrgil migration routes, Ierne is confirmed to be relatively close to Arcana in the Star Wars galaxy. Perhaps it will be featured in future Star Wars projects down the line.
14 Garel 
Garel was first featured in the Star Wars Rebels animated series. Located in the Outer Rim in the Lothal sector, the world was temporarily used by the Rebel cell known as the Spectres and Phoenix Squadron during the Empire's reign as a staging ground during their efforts to sabotage Imperial operations. However, the Rebels were eventually discovered by the Empire and were forced to flee.
13 Lothal 
The homeworld of Jedi Ezra Bridger, Lothal was a key world the Spectres sought to protect from the Empire as seen in Star Wars Rebels, though their continued presence also made the world a key target. To that end, it was on Lothal that Ezra used his bond with a pod of purrgil to send both himself and Grand Admiral Thrawn into hyperspace to be exiled for years outside the known galaxy as confirmed by Ahsoka. Following the Liberation of Lothal, Sabine Wren chose to stay, honoring Ezra's sacrifice and ensuring that his home would continue to be protected.
