Well, maybe there is still hope for a <insert rare/mythical beast name> hunt in <insert regional name> DLC, or a <insert very isolated/small culture name> DLC.
In all seriousness though, I am not at all excited by the reports of a Charlemagne DLC. That may change depending on what is expanded upon in the game. If they can do a good job fleshing out the generic pagan blobs and giving the player more to do in peacetime, I'll start changing my tune. At least this time, it looks like the player won't have to deal with the Karling superblob at start.
If the timeframe pushback was inevitable, I would've loved to have seen it go back another hundred years or so. You could see how the Muslim conquests of the Sassanids and the Byzantines played out as an Islamic conqueror, and perhaps taken Europe. You could've turned the tide as a Zoroastrian decedant of Kousrau II who saves the Sassanids from being absorbed into the Islamic Caliphate then finally put the final nail in the coffin of Persia's mortal enemy of Rome/Byzantium and get vengance for Heraclius' reconquests a few decades prior.
In the West, you could play in Ireland/Tutorial Island and renact the rise of the High Kingship as the Ua Niells or another family. In England, you could play the role of King Arthur as a Romano-British ruler who pushes back the invasion of the Angles, Saxons and Jutes... or played as conqueror.