User blog comment:Master Sima Yi/Assassinews 05-08-'14 – Assassin's Creed: Rogue announced/@comment-4254431-20140905131951/@comment-3046679-20140905144609

They're there for wrap-up reasons, Crook. Any money says Shay will murderize Ade, which fills the "Adéwalé himself was murdered in 1758", and probably cripples Achilles, explaining his limp, and after his hunt is over, Achilles' depression.

And in the end, Shay will probably grow a conscience again, and Haytham will put him down, to tie in with the fact there wasn't a blip about him in AC3, since the character didn't exist back then, so they have to blink him out of existence before the events of the revolution. Otherwise you have relevant questions, like why didn't the Templars just send their ultimate Assassin-killer who basically purged them on his own some years earlier, after Connor and his ilk.