It was previously reported that "Attack on Titan" season 2 has been delayed as the studios behind the anime are waiting for the manga source material to complete the necessary story arcs before they adapt the story into an anime. However, according to a new report from Breathe Cast, the delay may be also be due to another project the studio is working on.

According to the report, the primary cause for the next season's delay was the production on "Kabaneri of the Iron Fortress." 

"As I get through 'Kabaneri of the Iron Fortress' production, I am also continuing my work on the second season of 'Shingeki no Kyojin,' so I have had many discussions with Isayama-sensei," explained Wit Studio director Araki Tetsuro, who had been collaborating with "Attack on Titan" series creator Hajime Isayama.

The report points out that this clarifies the confusion regarding the previous rumor that the studio was waiting for more story arcs to adapt. Fans have pointed out that the two story arcs already available have enough material for an entire second season consisting of 25 episodes.

Given that the anime series will be sticking close to the original source material, the second season is expected to deal with the revelation that the Reiss family members have the ability of turning into Titans and the civil war that will wage against the throne just as the war against the Titans escalates.

According to a report from HNGN, season 2 will reveal the true origins of the Titans and how they tie into the last civilisation of mankind. The origin of the Titans was not touched upon in season 2 but it was revealed that they are not always large, brain-eating beasts and can transform into humans. 

With the delay, it is undetermined at this point when "Attack on Titan" season 2 would officially launch although it is speculated to release prior to the end of the year.