Well, that was fast.
It looks as if yesterday’s reporting from Deadline was inaccurate on Warner Bros. regarding adapting Attack On Titan, according to representatives on behalf of Kodansha as reported by Yahoo! Japan. Initially, Deadline’s piece stated that the studio was involved in negotiations for Fantastic Beasts And Where To Find Them helmer David Heyman to direct.
I suppose the good news here is that Yahoo! Japan’s report, as cited by Crunchyroll, suggests that several talks are underway. Nevertheless, it could be a case of the news being too soon aside from just being false if there are talks. At any rate, it appears this latest buzz just got cold water thrown on it.