I feel that Rebels is just to build up hype for Episode 7. Season 2 will premiere in early September and end before Dec 18th, when the movie comes out. Then the series will end, to be replaced by something else.
iirc this has all but explicitly been stated by Disney.
Between the abrupt ****ing of TCW in favor of Rebels and Battlefront 3 being set entirely during the Galactic Civil War, Disney has been making a concentrated effort to get the prequels out of as many peoples' minds as possible. They want the fans to be thinking about the OT, which was more highly regarded and which Episode 7 will be the direct sequel to. This is why pretty much all PT-era focused content has stopped.
"The Daemon lied with every breath. It could not help itself but to deceive and dismay, to riddle and ruin. The more we conversed, the closer I drew to one singularly ineluctable fact: I would gain no wisdom here."
Yeah, maybe 2 was a little too hasty. 3 seems like the golden number, since they said season 1 was very much a new hope and that season 2 was very much empire strikes back. season 3 will probably be very much Return of the Jedi.