Board Thread:General Discussion/@comment-33419273-20171020225732/@comment-26397825-20171027022833

No, they said that they are doing it  because  the powers would seek out the other half, which is in Cinder. What they didn't know how it would turn out is how Pyrrha would be affected with Amber's soul and half the Maiden power shoved in her.

The two halves seeking each other out and joining back together was never in question.