Unfortunately for Connor his story is over, there is nothing in history which could include Connor. Even the Civil War would be out of his reach (would be around 100 year old at that point lol)

So it will be a new hero if they make a new one, I am hoping Japan and the end of the Bushido ways, which started to decline early 19th Century. Hell even Connor with nothing left may have left for Japan, since many western nations wanted to trade with them at that point. Even Americans were employed to teach the Japanese how to fight against the remaining Bushido/Samurai warriors against the current emperor.

I would love it to be Japan, the scenery etc would be sublime.

People have been saying "I hope it is London" etc, nahh not London, its boring, smog and rooftops lol Although the smog would be easy to conceal in, it is just too dark.

French Revolution would have been good but so close to AC3 in time line.

WW1 or WW2 would have been excellent in France, ok it would look depressing, but the French Resistance of WW2 would have been a great cover story for a new Assassin character.