Not necessarily delete permanently, but, until more verification is available. If Le Monde denies it, need more reliable sources.
The claim that the interview appeared in Le Monde is clearly a fabrication. (I don't think this is simply a matter of someone forgetting the proper source.) What I'm saying is that this information about its being fake news should be kept in the threads. Deleting the threads themselves would remove it.
If the moderators can put a note in the first post, pointing out the Le Monde denial (and perhaps the obvious inference that this is fake news) that would be helpful. I think the threads themselves should remain, though.
I may not have been clear enough in my previous posts. When I said, “I’ve found far more pages in which the story is cited with no denial”, my aim wasn’t to cast doubt on the denial but rather to point out how important it is that threads that include proof that this story is phony be kept on the net.