My theory for 7 havens

First of all, this theory revolves around me thinking that Korra wouldn't destroy the world. my personal belief is that Korra felt the weight of her being the cornerstone of a new avatar cycle and even without guidance from past avatars wouldn't mess everything up on the first iteration, but that doesn't change the fact that the story takes place after the avatar destroyed the world. My theory revolves around Vaatu and the creation of the dark avatar. if Raava fused with Wan, becoming the avatar, and after Wan died, getting reincarnated. Then who's to say the same couldn't happen with Vaatu fusing with Unalaq and getting reincarnated after he was defeated by Korra? My theory is that Korra died young, which you'll have to hear me out on. In ASH's lore, Pavi, for whatever reason, was born many years after Korra's death. this would have given the dark avatar, who people would have seen as the one and only avatar, to wreak havoc on the world and be seen as the avatar, leaving a world for Pavi to deal with. Again, I haven't finished LOK yet or looked at this subreddit enough to see if this is a theory that people already have, so please let me know if I got anything wrong.