Okay, see I had a theory about this months ago. I'll put what I can remember.
Basically, it can, if something destiny changing happens.
Like meeting and marrying your soul mate, or becoming a princess, which I thought of before season two had even ended.
To sum it up, basically only an outside force, one that is essentially harmony magic, which is something only element bearers can ever use, changing it in a major or minor way.