I will watch Ewan McGreor as Obi-Wan in anything. I picture it as something like an old episode of Kung-Fu in space. Someone else as Obi-Wan would be an uphill battle.
Unless of course the give us The Young Obi-Wan Chronicles that follows a young padawan Obi-Wan on his adventures with his mentor Qui-Gon, also portrayed by a younger actor.
I would love the see a young Obi-wan with Qui-Gon, Liam Neeson reprise his role teaching him. However, with Disney owning Star Wars and Marvel, they have a lot of shows on their plate right now between the two franchises.
There could be flashbacks that Obi-wan has in this series where Qui-Gon could be teaching him something in the past, that he uses in that particular episode, just so he could cameo in the series, besides just being a voice. I hope Frank Oz has a few lines too.
I wouldn’t be surprised if one or two shows between Marvel and Star Wars don’t get off the ground.