The production of the third season of Tokyo Ghoul might be on hiatus due to the development of the franchise's live-action movie, but rumors about the upcoming third season of the anime continue to emerge. Among these, of course, is the speculation that there might very well be a Tokyo Ghoul Season 4.
If rumors about the upcoming anime prove accurate, the third season of Tokyo Ghoul would most certainly stay very close to the manga's events, taking a route that is completely opposite of what the anime's second season took. Indeed, Tokyo Ghoul Root A diverged completely from the manga, and it resulted in a lot of fans being dissatisfied with the results.
Thus, rumors have recently emerged that the Studio Pierrot is currently looking into a more manga-centric adaptation for the anime's third season. Over the last few months, the Tokyo Ghoul:re manga has been building up for what seemed to be the climax of the franchise, as protagonist Kaneki Ken, who is now known as Haise Sasaki, battled his mentor, the seemingly unbeatable Arima.
The battle of master and student lasted a number of issues in the manga, and from the sheer epic scope and immensely high stakes of their battle, it seemed to be the perfect ending to the Tokyo Ghoul storyline. If Tokyo Ghoul Season 3 would indeed stick close to the manga, the anime would probably feature the Sasaki vs. Arima rematch as the final battle.
Doing so would make Tokyo Ghoul Season 3 into one intense ride, as the story of Kaneki Ken practically goes full circle with his rematch with the strongest ghoul investigator. If any, ending Season 3 with their rematch would make the third season into the best Tokyo Ghoul adaptation yet.
However, if the manga's events are anything to get by, there is a lot more to the story after the conclusion of the Kaneki vs. Arima rematch. In fact, after epic their fight, creator Sui Ishida appeared to be introducing yet another arc for the manga.
With another arc starting after the rematch between Kaneki and Arima, the story of Tokyo Ghoul would definitely expand some more. With this said, it is quite safe to say that there would probably be more than enough material to warrant yet another season of the Tokyo Ghoul anime.
This would only happen, of course, if Studio Pierrot will listen to the franchise's fans and stick close to the plot of the manga. If the anime studio decides to pull a Naruto Shippuden instead, then Tokyo Ghoul fans would have to muster a whole lot of patience once more.