Ngl I'm very happy with my excuse for Obi-Wan knowing jackshit about Galidraan in Smile for the Camera. Like yes, there's the classic "he was thirteen, so not exactly getting reports on missions, on Melidaan around that time, and more focused on recovery from trauma and malnutrition than on gossip or even public announcements about it."
But! Phindar. Obi-Wan got a partial memory wipe that year. Easy way to miss things.
And yes, he might have learned about it from Mandalorians during the Year on the Run, that would be a great time and reason for him to learn about it... but you just KNOW he got multiple concussions without proper medical care while living hand to mouth with Satine.
The man's memory is full of holes and unfortunately those holes are peppered over the exact times one might have learned about Mandalorian politics and the Senate using Jedi as a weapon through misinformation.
Just one of these excuses is decent enough, but all three? Even Jango can't get mad about it. The fuck was Obi-Wan supposed to do?