I was aware of the Piaf version. She has fans here at the Lutherie Arms. I looked more closely at the notes for the video of the Legionnaires singing; those were the actual coup participants, singing in prison.
I read the translation included in my first link above; it is better and more natural sounding than the one included in the original post. I can see why you'd say it's predictive rather than a warning, except for the part here
"However, if nothing is done, heedlessness will continue to spread its poison throughout society, inexorably. In the end, there will be an explosion, and our comrades in active military service will be forced to step in and undertake the perilous mission of protecting our civilizational values and the lives of our fellow citizens."
I understand that several of the serving officers who signed the letter are to be cashiered.