Chapter 71 of Shingeki No Kyojin was supposed to answer questions about the identity of Grisha Yeager and his connection with former Survey Corps leader Keith Shadis, but it apparently left more questions instead.
Entitled the Bystander, Attack on Titan latest chapter focused on Shadis and his relationship with Eren's parents, and gave a shade on the true origin of Grisha Yeager before he even assumed such name.
By dissecting Shadis' account of story alone, it appears the two men met 20 years ago outside Wall Maria. Shadis, who was then fledgling Survey Corps member, found a man surprisingly roaming outside the Walled City. He also noticed that Titan activity at that time was minimal to his surprise, but he was nevertheless perplexed to see a man daring to go outside Wall Maria despite the ominous threat of the Titans.
While the succeeding episodes of Shadis' narration are quite intriguing and will certainly hold more value as the story progresses, the first sequence alone ruffled feathers already and left a crack on the previously accepted fact that Dr. Yeager is a citizen of the walled city since the day he was born.
The controversy Shadis' revelation created compelled its fans to concoct theories about Eren's father whereabouts, and most of them are starting to believe that he came from the place where Bertolt, Reiner and Annie are from. His relationship with the Ape Titan, who is eagerly waiting for Eren and the Survey Corps in Shiganshina district, is also in play largely because of their resemblance to each other, not to mention dwarven ears in their titan forms.
Perhaps, author Hajime Isayama is already planting the seeds for what will likely be an epic chapter 72 and onwards, when Eren clashes with the Monkey Titan in the place where it all started.