I believe that revisionism is in itself essentially a historical exercise. I'm looking for something that can succinctly describe the following scenarios where the "revisionism" is more immediate and possibly necessary. I'm open to both terminology and colourful idiomatic expressions.
John Doe is the leader of the revolutionary army. He is, however, hit in a drive-by shooting and dies instantly. Later on, his second-in-command informs the army that their leader didn't die instantly and actually survived for a few minutes. He states that John Doe's last words were, "Don't lose heart and keep on going without me. I'll be watching over you from the heavens.".
The miracle of the herring is an usual miracle ascribed to St. Thomas Aquinas, mainly out of desperation on the part of the Catholic Church because, although he was a great writer, he did little in the way of sainthood. Therefore, they created this miracle. The story goes that St. Thomas Aquinas was on his deathbed and wanted some herring, but there was no herring where he lived (the Mediterranean) so they gave him pilchards instead. When Thomas ate them, he said they were the best herring he ever tasted. The church claimed that the pilchards turned into herrings in his mouth.
(I'm not sure how much time passed between Aquinas' death and his canonisation. For the purpose of this question, let's assume that this interval was relatively brief.)
Edit: I'm concerned more with the act of revisionism to advance a cause than its end result or the subjects involved.