Star Wars: The Bad Batch Season 3 Ep 9-12 - Review!

In defense of Ventress' appearance, I think the most compelling reason for her to appear over any other force user we know is her parallel with Crosshair. Omega directly points this out when they discuss whether they should trust her, saying that she didn't give up on Crosshair's redemption, so why should they doubt that Ventress could have improved, too. I haven't read Dark Disciple either, but I think they did a good job characterizing Ventress and her character change for both readers of the book and for people who haven't seen her since Clone Wars Season 5. For non-readers, she already seemed on the path to a possible redemption in Clone Wars with her leaving the Separatists and helping Anakin clear Ahsoka's name. Her new look, new lightsaber, and new demeanor give the strong impression that she's been through some heavy stuff since we last saw her, which I think make her actions believable. For readers of the book, I've heard a lot of them point out visual and character references to her character arc in that book that make it seem pretty in line with what happened, sans the dying part. On the subject of the shows retconning books and comics, I see these retcons more as a retelling of the same story in a different way. I have a limited knowledge of the Ahsoka novel and Kanan comics, but I think both those stories and their retcons tell the same broad strokes of the story, just with some of the specific details altered to fit the medium and story they're tying into. No major, character- or plot-defining details seem to have been contradicted, so I find these to be more acceptable retcons, especially considering most show watchers haven't read any of the books or comics.

If I can voice a slight contrarian opinion: As a big fan of Ventress and of Dark Disciple I'm actually totally fine with them retconning her death. Like a lot of the stuff in this era her death felt less like a natural conclusion to her character arc and more like the writers feeling the need to explain why she's not around for the original trilogy. I feel like now they've become more comfortable with just saying "yeah they weren't in the movies, so what?" and I'm fine with that. I'll agree that it's probably the weakest episode of this season but it was a "quiet before the storm" episode which I think was an important tonal beat to hit. And I think Ventress's post redemption arc characterisation in the episode does totally follow on from where she is by the end of Dark Disciple.