At Star Wars Celebration, the Star Wars Rebels team, including showrunner and Executive Producer Dave Filoni revealed that the upcoming 4th season would be the last for the beloved show. Filoni noted that he wanted to end it on his own terms, and if that trailer is any indication, he will.
But the big change though for the final 15 episodes is that the format is going to change. Instead of being all self-contained stories, they’ll weave together in a giant serialized arc. He tells IGN:
“Season 4 is unlike any other we’ve ever done in that, at a certain point, a couple of episodes in, it’s more one continuous story arc all the way to the end than it’s ever been, in anything we’ve done – even Clone Wars – where each story really fits together, Yes they’re unique and independent, but it almost feels like day-to-day. Things start to move fast and get really exciting and interesting and desperate and awesome – and we’ve never done that before, and it’s really exhilarating.”
Give that it’s the last season, it honestly does make sense that they do it this way, as they have a lot of things to reveal before the end, mainly, the fates of just about every character.