Ashley Eckstein told Cinema Blend that she thinks it's crucial to watch Clone Wars, Rebels, and even Tales of the Jedi to fully appreciate Ahsoka:
I actually recommend to everyone who is excited about the upcoming Ahsoka series, I highly recommend that you take the time to watch Clone Wars, and watch Star Wars Rebels, and even Star Wars: Tales of the Jedi. Because if you don't, you're going to miss out on crucial, crucial backstory that you really need to know to fully enjoy the Ahsoka series, which is so exciting.
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We're gonna get so many new and incredible stories, but without that backstory, and full understanding of who Ahsoka is and even who the other characters are, you're not going to have as rich or in-depth of an understanding and appreciation of what's going to happen in the series without the backstory, so I'm very grateful that Clone Wars and Rebels and Tales of the Jedi are on Disney+. Any chance I get, I tell fans, 'Go and watch it and binge it before you watch the Ahsoka series. It's really gonna matter.'
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And then Clone Wars and Rebels and even Tales of the Jedi in general... You know, at some point, most Star Wars fans go back and watch the movies. They watch Episodes IV, V, and VI, and I, II and III. Well now, Star Wars: The Clone Wars and Star Wars Rebels, they're a part of that timeline. It's part of the story. It's part of the overall trajectory and journey of these characters, so without watching those series, you're kind of missing out. They're all connected. I highly recommend that fans watch them.
While I have obviously watched all of those shows, this show will completely sink if it actually requires all of that. The vast majority of the general audience of this show will be going in knowing (in general) the movies, probably The Mandalorian and maybe BoBF (even if they've seen Obi-Wan/Andor, those shows don't seem very connected to this one).
Most people that watch this kind of thing, aka the people that make up most of the audience, are casual SW fans and don't watch the cartoons, especially adults. Now I love a lot of in depth continuity, but requiring TCW/Rebels for a (presumably) expensive, mainstream live action Star Wars project is just a terrible idea, they need to have found a way to give people backstory and possibly make them care about characters from TCW/Rebels without requiring people to go watch literally hundreds of episodes of TV.
Its what I've been worried about since the beginning. To use a personal anecdote, my Dad and younger brother like Star Wars, and really like The Mandalorian, but wouldn't watch a second of any of the animated shows if you paid them. They're both interested in Ahsoka because of the character's Mandalorian and BoBF appearances, and just liking what seems to be some good Force user action. If the show tries to just shove the Rebels characters at them they're probably just going to not care, and possibly be annoyed unless the characters are written in a way that makes them understandable, and hopefully appealing, to people that never saw them in the cartoons.
Of course this is article is just someone promoting the SW shows in general, hopefully the writers of Ahsoka took into account the average viewer of a live action SW show not watching TCW/Rebels.