There's a chance AC Shadows' climax is the Honnō-ji incident

For those unaware, the Honnō-ji incident was the assassination of Oda Nobunaga by his vassal Akechi Mitsuhide in 1582 (3 years after the start of the game). Akechi would then be killed 2 weeks later by Toyotomi Hideyoshi (Taiko in FX's "Shogun"), who would go on to finish the unification of Japan which Nobunaga nearly completed.

The interesting bit is that to this day nobody really knows for sure why Akechi betrayed his Lord or even where Nobunaga's remains ended up. That's where I feel the game's likely to try to fill in the gaps. I imagine Nobunaga, Akechi, Hideyoshi, and probably even Tokugawa Ieyasu will all be relevant characters in the context of the game. They could pretty easily dress up Nobunaga as the head Templar for this game, and let the MCs in on the plot to assassinate him.

This is another reason why I'm actually really on board with Yasuke being one of the MCs. Historical records surrounding his life are scant, but Nobunaga basically bought him from the Jesuits because he had never seen a black man before and he wanted Yasuke to walk around his city as an attraction for the Japanese citizenry. There's a lot of debate in regards to how large his role was during the 15 months he served under Nobunaga, but he was at least around during one of Nobunaga's greatest victories against the Takeda clan, and was in Japan at the time of the Honnō-ji incident. After that, nobody really knows what happened to Yasuke, though the most likely theory is that the Jesuits reclaimed him.

Seeing as he's one of the two leads for this game, it's very likely that his relationship with Nobunaga will be central to the plot. I'm curious to see if AC's version of Yasuke feels strongly about honor and loyalty like most typecast Samurai, or if he resents his new master and assists with setting up his assassination.

Either way this period has been my most anticipated AC setting since I first played AC2, so here's to hoping it delivers!