The Star Wars: Tales series has added much depth to certain characters of the Star Wars franchise. Each series has given us more emotion and backstory to some familiar fan-favorites and others that we are very curious to know more about. I hope Lucasfilm Animation continues these shorts, and as a fan, I have a suggestion for the next one:
Tales of the Rebellion.
You could go many directions with stories of the Rebel Alliance, but I think two characters could work well together under the Star Wars: Tales format.
The first being focusing on Luke Skywalker and his time between the events of A New Hope and The Empire Strikes Back. There is a gap between what occurs in both films that's only been explored in books and comics so far. It would be a very interesting period to explore on the small screen.
Luke will always be well-loved and popular with audiences, in my opinion. His decision to continue his path with the Rebellion, along with figuring out how to be a Jedi, would be a good story to tell. You could also have side but popular characters, like General Rieeken and Wedge Antilles, appear in the series.
To tie it in, though, Lucasfilm should focus on the birth of the Rebellion that was hinted at in Solo: A Star Wars Story. The character of Enfys Nest, who took on the criminal empire of Crimson Dawn in the film, spoke of rebellion of being victorious with Han Solo.
She is a character that I am sure many fans would love more content and backstory for, too, and would be a welcome addition to the Tales series. She was portrayed by British actress Erin Kellyman in the film. Kellyman is only 26 and could easily voice the character if brought back.
In the novelization of Solo, Enfys Nest takes the coaxium they got from Crimson Dawn to the character of Saw Gerrara. There, she meets a younger Jyn Erso before the events of Rogue One: A Star Wars Story. It is a very interesting tie into the Rebel Alliance as a whole. Imagine if Enfys Nest was one of the earliest leaders of the growing rebellion, and how that could be displayed in the series. It would be very valuable to learn and be able to tie in the beginnings with her to where Luke and the Rebel Alliance were when they were on the Ice Planet of Hoth.
As more Tales series may be produced, I hope they look at characters who have had much screen time and less screen time. Either way, both Enfys Nest and Luke Skywalker may have more animated stories to tell.