Except that Aku no longer exists.
Remember that Ashi disappeared at the end of the episode, that means there no longer is any Aku to create the doomed timeline in the first place.
So the old timeline no longer exists in any form, with perhaps the possible exception of Jack's defeating of the Lava Monster who most likely is still in Valhalla (due to the fact that Jack cannot effect any divine beings, powers or artifacts) even after the timeline was changed.