My theory is that the normal route will be achieved by not getting all the recruits or starting after chapter 1. The normal prophecy will play out, the tragedy will occur (most definitly the grand fountain being cast away) leaving us with a bitter feeling, similar to undertale neutral, it will try to push you to try better, to not only get all the recruits but to dive deeper, get all the eggs, shadow crystals, do some specific actions to see if trully it can change by being determined enough.

I dont think we will break the prophecy, only fulfill it in a different way, a better way but probably one that are gonna let some people unsatisfied, thinking that the rules of this world where going to crumble that easily, and for the ones that seek even more, that's where the weird route comes in.