I think (again) that this problem is mostly because the way origin characters works. The fact we possibly roleplay as one of them means we know everything about them from the get go. So when we discover Astarion is a vampire, the game plays it like some big reveal but after months of telling us of each one of them and their full origin this just doesn't work. Same with shaowheart and Shar and Wyll and his demon. This mechanic is a nice idea, but it just doesn't work narratively. And it's a recurring problem with Larian, which seems to care more about cool gameplay mechanics than cohesive narrative, and are willing to sacrifice the narrative in favour of cool gameplay ideas
