Via Slashfilm.com:
The trailer for Star Wars Rebels Season 3 premiered at Star Wars Celebration Europe 2016, revealing a new villain for our heroes. But with Grand Admiral Thrawn resurrected from Legends back into Star Wars canon, what does this mean for Darth Vader and his Inquisitors? Will we see the Jedi-turned-Sith leader or his Force-empowered Jedi hunter team of Inquisitors in the third season of the acclaimed Disney XD series? Star Wars Rebels creator Dave Filoni answers these questions, after the jump.
Will We See Darth Vader in Star Wars Rebels Season 3?
I had a chance to ask Star Wars Rebels creator/producer Dave Filoni if we will see Darth Vader in Star Wars Rebels Season 3, here is what he said:

You know, I’ve kind of gone on this course, which is pretty, pretty direct about certain things ’cause I don’t like to tease people along and then have them be disappointed. So it’s really an elected decision to not have Vader around because, as we get closer to A New Hope, I want him to serve as that story.

Filoni explained that he doesn’t want to “take up too much of Vader’s time.”

I know it sounds funny. I don’t wanna fill in every hole. I don’t know what we benefit from that. As much as you need to say, okay, this is a major point in his life when he’s confronted by his former apprentice. That is worth doing. Him chasing the rebels of the Ghost crew around is never something that really interested me. Mainly because I didn’t think they could survive it for very long. And now that I have Thrawn, it’s more interesting to me to setup this completely different kind of villain that’s gonna play a long game against our guys that they’re not typically used to.

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