During an interview with Josh Horowitz from the Happy Sad Confused podcast, Ewan McGregor revealed that he did a full costume test for the upcoming Kenobi series on Disney+ while on the set of The Mandalorian with Kenobi showrunner Deborah Chow.
JOSH HOROWITZ: “How’s the lightsaber training, are you ready? This is a long time coming. Do you feel ready to get back on set and return to Obi-Wan?”
EWAN McGREGOR: “Yes. I really am very excited about it. It’s been a long time coming. I mean we’ve been talking about doing it, Lucasfilm and Disney, I dunno for four, five, maybe more years and it’s just taken a while to come to fruition. I am excited about the fact that it’s a series as opposed to a movie, it gives us more space, and mainly I am excited about it because of The Mandalorian series which I just thought was really good, and we’re going to adopt some of that technology that they utilized in that filming and I’m working with Deborah Chow who directed some Mandalorian. I’m really excited about working with her, I think she’s really good. We did a couple of tests. When we were going to make a film earlier we did some testing and it was great working with her.”https://www.starwarsnewsnet.com/2020/10/ewan-mcgregor-did-in-costume-camera-tests-for-kenobi-disney-plus-series-on-the-set-of-the-mandalorian.html
HOROWITZ: “Did you actually get into character or was that to premature for a camera test?”
McGREGOR: “No, we kind of did it properly. It was funny walking on set because it was a lot of The Mandalorian crew and I walked on, and for it was a big moment, I walked into the dressing room and there were my beige cloaks and my belts and boots and it was like, oh my God, it was my old costume, it was amazing.”https://www.starwarsnewsnet.com/2020/10/ewan-mcgregor-did-in-costume-camera-tests-for-kenobi-disney-plus-series-on-the-set-of-the-mandalorian.html
So, based on how this is phrased, it seems like Deborah Chow has been attached to this Kenobi project even in the phase when it was still being developed as a feature film, and from what it seems, the idea of this being a feature film persisted all the way through filming of the first season of The Mandalorian. Very interesting to see how quickly the pivot between the film and the series happened after the success of Mando S1.
There is no official release date for the Kenobi series on Disney+, but Ewan McGregor has confirmed, at least to the best of his knowledge, that filming is planned to start in March 2021.