Sorry for not saving the previous text, formatting was getting to be a bit of a mess.
I do see that the page Yann linked to was created around the same time action was taken, by Cary, and lists the reason for the deletions and the content deleted. I'll assume this page was linked in several other places on fr.wikisource and didn't go unnoticed. It does seem to be that Yann is objecting to the enforcement of the demand, and perhaps the communication issue is less one between WMF and community and more (if anything) between WMF and the poster of content subject to a takedown.
I'm curious why the Foundation doesn't take direct action when it is responding to a takedown notice - is it not relevant to these notices whether the recipient or someone else takes the action requested?
While Yann did mention you and Cary by name, he did not accuse either of you of intentionally omitting or misleadingly characterizing facts. This isn't a court, perhaps it would be better to assume (or at least pretend to assume) good faith error on his part.
Nathan