Attack on Titan has always prided itself as an anime that never pulls punches when depicting the finality of death. Indeed, through the course of the anime's first season, a number of notable deaths were featured, and in each instance, the death was always final. There were no characters who came back to life simply because of plot armor.
Thus, with regards to the latest chapters of the Attack on Titan manga, it would seem like the story is already drawing to a close. If the events of Chapter 82, the latest issue that has been released, is anything to go by, the Attack on Titan saga definitely feels like it is ending, with main villains being faced and main characters dying in valiant ways.
Interestingly, the two prominent characters that seem to have certainly died as of the manga's latest chapter were Erwin and Armin, two men who were considered as the brains behind the Survey Corps. During the previous chapters, Erwin seemed to have been killed while initiating a suicide attack on the Beast Titan, while Armin seemed to have died after sacrificing himself to beat the Colossal Titan.
Thus, fans of the franchise simply could not see any other comparable character that could replace these last two alleged casualties. Though characters such as Hange or even Jean are quite capable, they do not possess the same intelligence and cunning that Erwin or Armin possess. With this in mind, numerous fans are speculating that there is simply no other way for the plot to go than towards its end.
After all, the Attack on Titan saga has all but gone full circle, with the now-mature Eren and the other Survey Corps soldiers battling it out in the same village that was breached by the Colossal Titan years before. The leader of the titans, the Beast Titan, has also been engaged in battle by no less than Levi, the strongest character in the franchise.
Hence, the end of the present arc of the manga seems to be in the inevitable conclusion of the Attack on Titan saga itself, and with the next season of the anime featuring events of the present arc in the manga, it would really seem like Attack on Titan Season 2 would be the final season of the anime.
With this in mind, the long wait for the anime's second season would surely be worth it.