For the most part, Disney has done very well with its animated Star Wars series. One of them, Star Wars Rebels, was an unmitigated success that was popular with fans and critics alike. Yet, while fans have wondered if new Rebels episodes will ever be made, that probably shouldn't happen.
When Cartoon Network cancelled Star Wars: The Clone Wars years ago, Netflix stepped in. It picked up the streaming rights to the existing five seasons and worked with producers to create Season 6. The intention at the time was to wrap up the story in a way that would lead the show into the third prequel film, Revenge of the Sith. However, Season 6 didn't really address the dangling plot threads of Season 5, leaving fans unsatisfied.
That feeling got even worse when Rebels debuted. At the end of that show's first season, Ahsoka Tano reappeared. The last time fans saw her was when she walked away from the Jedi Order at the end of the fifth season of The Clone Wars. Eventually, other characters from The Clone Wars showed up, too, including Captain Rex. This left fans wondering how the two popular characters made it through Order 66.
The story arc of Rebels made a seventh and final season of The Clone Wars necessary, and it was there that Ahsoka and Rex's survival was ultimately explained. Disney also used the season to debut a group of irregular Clones called the Bad Batch, with their introduction serving as a backdoor pilot for a spinoff series about them.
By design, The Clone Wars can support almost infinite stories. While Obi-Wan Kenobi, Ahsoka Tano, Anakin Skywalker and Captain Rex are considered the principal characters, there are entire stories and arcs that don't use any of them. For example, the first episode is about Yoda and a different group of Clone Troopers dealing with Asajj Ventress on Toydaria. The Clone Wars is filled with stories about other Jedi, Clones, bounty hunters, droids and more.
Because of that, new episodes can be created at any point in the timeline of The Clone Wars. While Anakin, Obi-Wan and Ahsoka were busy during the now infamous Mortis Arc, there were other stories that could easily be told about Quinlan Vos, Cad Bane or Asajj Ventress. Frankly, fans would probably like to see more stories set during the Clone Wars about any and all of those characters.
Yet, Rebels isn't like The Clone Wars. All four seasons center on the Rebel cell known as the Spectres and their ship, the Ghost. The series features other characters, many of whom were part of The Clone Wars, but the narrative focuses almost exclusively on the six main characters. The result is a much more self-contained narrative than the other animated series.
Telling stories focused exclusively on the Spectres after the end of Rebels would be difficult as Kanan Jarrus and Ezra Bridger sacrificed themselves to defeat Thrawn. There could be episodes set before Rebels to show how the characters ended up on the Ghost before meeting Ezra on Lothal. The problem is they then wouldn't be together until the moment they find Ezra, yet what made this series work was the group's chemistry.
Realistically, the only place to insert new episodes in Rebels' timeline would be in the midst of the existing seasons. However, that would also be problematic because Rebels was a well-plotted narrative, so for all intents and purposes, the story has been told, and told well. The story is complete as it is, leaving little room for more episodes. While the various characters from both shows will show up in other series, the time for Rebels has passed. No one would be surprised to see spinoffs, though.
All four seasons of Star Wars Rebels are also available on Disney+.