The good news is that a major Rebels character could potentially appear in an upcoming project in the Star Wars franchise: Solo.
As the second anthology film of the franchise, Solo: A Star Wars Story is set between the events of Revenge of the Sith and A New Hope, which means that former-Jedi-in-hiding Kanan Jarrus could totally show up.
The fourth and final season of Star Wars Rebels is coming to an end on Disney XD in the not-too-distant future, and only a couple of characters are guaranteed to appear in the Star Wars saga beyond the series finale.
In fact, aside from Hera and Chopper, we can’t even be sure at this point which characters will survive.