You're trying to insert purpose or intent into what is essentially accident. Most -- almost all -- changes like these either never have lasting consequences or are eventually undone. They are insignificant, and may not even have expression, unless and until they become significant because of subsequent changes.

You can insert supernatural interference into the process -- there's nothing but the principle of parsimony (Occam's razor) preventing that -- but you can't require it in order for things to work the way they apparently do/did work.