I feel that the whole set up, with the Dark One and Pattern at least, is an artificial construct put on by the Creator, to allow all possible aspects to be present, without the Creator's own demise.

I guess I like to think that the world itself and the people / souls within it can continue on without the three, but the presence of only the Dark One or the Creator would unbalance it, so both need to be removed, and with them the reason for the Pattern to be there.