does an "issued" a threat become "rescinded/revoked" when acted upon?
Solution 1:
The best term for this purpose can be found within the question itself: the threat has been carried out.
The terms such as revoke, withdraw or rescind are indeed all inappropriate in this scenario. They are appropriate only if the threatener changes his mind before the time for the other person's doing X, and communicates that to the other person, so that when that time comes, the person is no longer under threat.
Incidentally, it is odd to use the word promise for a threat. A promise is normally something that is to the benefit of the promisee.