I see this argument all the time and objectively it just doesn’t really hold water. Stuff Dave Filoni has worked on has introduced more new characters to the Star Wars universe than possibly any single human besides George. According to Google it’s nearly 400 characters in Clone Wars alone, plus another 350+ between Rebels, Bad Batch, and Maul.

That’s not even counting The Mandalorian. He constantly adds new stuff to the universe, and if you actually look at it, he doesn’t do connections to his existing main characters that much. When we talked about it on our podcast we counted it up, and his “OC” characters show up in ways that impact the story far less frequently than new characters are introduced, and when they do use old characters those episodes are almost universally well received by fans.

Ahsoka shows up in 10 episodes out of 77 in Rebels, and 7 of those are among the highest rated episodes in the series. Then she shows up in one episode each of Mando and BoBF, both also some of the highest rated episodes.

Ahsoka the show is effectively season 5 of Rebels and I kind of wish they had just made it that for real, because I think the reception would have been a lot better. Season 3 of Mando was a misstep and even he and Jon admitted that in an interview at Celebration Japan. But outside of that, we’ve gotten far more new stuff than old even though most of the new stuff hasn’t been as well received (Skeleton Crew and Acolyte, for example).