I think that, due to the nature of chaos and the butterfly effect, any time travel at all would change the future. Unless it was just closing a time loop that was already present in the current past (which would mean any attempt to alter history would fail because that attempt is already a part of history), or if it’s possible to create new branches in time.

So these rules are either unnecessary because any time travel automatically causes changes that, it’s not possible to change the past from the past, or it’s not possible to go back to our past, thus nothing you do will affect our present.