The purpose of the Internet archive is to maintain history, and they are a really great resource. To do this though, they don't really need to make current content live - they could just as well have a 6-month embargo between archiving content and making it live. This would make it hard for anyone to abuse it as a way round censorship, at least for for timely content, which most terrorist propaganda is.
I'm not trying to excuse the French IRU's excessive and rather broken censorship requests, but the archive's current behaviour is ripe for abuse.