You should "Delete" the auto list rule if you think you will never going to use it again. When you Delete the rule, it is gone forever with no chance of recovery.
You should "Disable" the auto list rule if you temporarily want to ignore it but may wish to use it at some later point in time. When a Rule is Disabled, it is not processed and does NOT create any listings. The rule exists BUT for all practical purposes, it is literally ignored.