Here is some news that we regret to inform you!
According to Moviepilot and other several reports, the second season of Attack on Titan anime which was previously slated for release in this current year, now is indefinitely delayed due to some reasons concerns the manga.
The director of the Attack On Titan anime, Tetsuro Araki and the mangaka Hajime Isayama have both decided that the manga will always contain four story arcs ahead of the anime instead of 2 arcs in order to keep the alignment between the manga and the anime. The manga is currently only 2 arcs and the anime won't get the green light for production until the manga reaches to the 4 story arcs.
As reminder, the second season of Attack on Titan was initially planned to be based on more original content and very little elements from the manga.
Source: moviepilot