I don't think that a prophecy would help this issue for several reasons. The most obvious being that it seems people have generally lost interest in prophecy stories and playing chosen ones, so that's not gonna grab a lot of people. Secondly, what you're suggesting, while interesting, would require some structural changes to the game. I think that for it to work, the prophecy would need to be a central aspect of the story, not just a random addition. It would need to be something Tav considers and msues on frequently. The prophecy would need to be their story, and so it would need to be important. The prophecy has to DO something, it can't just just be an extra detail. That ties into whole thing you say about Tav automatically being considered the leader and Withers etc choosing to help them; it's not unique to Tav. If you play as an origin that stuff all plays out the same, which is the root of the problem. The game isn't about Tav and so long as origin characters exist the way they do, it can't be.
