Darth Maul voice actor, Sam Witwer, said during a Twitch stream that Starkiller may appear in Star War Rebels as an inquisitor
“Dave (Filoni) did share with me, by the way, he considered making Starkiller an Inquisitor in Star Wars Rebels”
Sam Witwer continues saying “It didn’t quite fit the story that they were telling, but he did think about it because he thought that would be interesting.”
Starkiller it is a non cannon Star Wars character from the Star Wars game The Force Unleashed and its sequel.
From what Sam told us the most plausible theory is that Starkiller was just an idea, but still Is it unclear if this will in fact we will see him in the next season of Star War Rebels.
What is sure is that we understand once again that Dave Feloni have a lot of imagination and have bold ideas.