Star Wars Rebels debuted all the way back in 2014 and concluded in March 2018. It ended on somewhat of a cliffhanger what with Ezra missing in action (along with Thrawn) and Ahsoka Tano and Sabine Wren seemingly teaming up to go out in search of him.
Well, rumours emerged just a couple of months ago which claimed that there's a sequel series to Star Wars Rebels in the works for Disney's streaming service. It's said that Ahsoka nad Sabine would be the stars and Star Wars: The Clone Wars supervising director Dave Filoni will be involved in some capacity.
This sequel series would presumably take place between the events of Star Wars: Episode VI — Return of the Jedi and Star Wars: Episode VII — The Force Awakens. Regardless, these are all just rumours. Ezra Bridger voice actor Taylor Gray recently told Bespin Bulletin that he hasn't heard anything about the sequel series other than the rumours themselves.
"I probably can't say anything," Gray began cautiously. "I don't want it to seem like I'm hiding anything, just don't really have anything to add on that. I haven't heard anything beyond the rumours online about a sequel."
So, either Gray simply hasn't been reached out to yet, Ezra simply isn't a part of the sequel series, or the rumours are pure poppycock. According to the rumours, the sequel series is planned for Winter 2020 so we should have them confirmed or refuted within the year — or coming months.