You know, I'm not gonna lie. I swear I was thinking about something like this a while ago. I kept thinking about how amazing it would be if Nolan did something like this, like in the 3rd movie what if Batman sacrifices himself to save a ton of people in the end, and it turns into a "The Legend Of The Dark Knight"
type of ending (or movie). I don't think this idea is too crazy at all. It'd be a ballsy yet groundbreaking move in the cbm genre, it's not like he hasn't already broke some ground with his first 2 Batman movies