No... no that doesn't make sense. Not because Obi-Wan's idealistic or naive, but because there is literally no way for clone troopers to rebel like that. Their loyalty is ingrained in their training from the very beginning, and anyway, Obi knows Cody like a friend. More than he knows Anakin in some ways.

No. This must be another group of 'troopers' and another war.

"I think you must be from the future, my friend. None of this is part of my time."