That's why I said "deus ex". If the story is not related to original plot - it is not a prequel, it is spin-off. If it related to the original story with the Damned One - we know it very good enough, there isn't so much left to put on the field, so what kind of possible Original Sin it could be, if not about the Sword of Lies and Damned One? It seems like they are coming up with something totally new thus "deus ex machina"element. I find them quite cheap, especially when it comes to universe/setting consistence, but that's just me, may be (too much Martin and Bekker).
Well, from I've read here the plot of this game will be concerned with the birth of the Black Ring, some exploits of Zandalor and Arhu when they were younger, and struggles with the Orcs after their tenuous alliance with the Council of Seven. These seem all pretty much tied in with the main story to me. It's filling in a big, open gap of time between the DD backstory and the events of DD itself.
Personally I have been hoping for a game set BEFORE the events of DD (which seemed like much more interesting time period) since the very beginning.
So in some ways this seems more connected to the "original story" than the meandering adventures concerning Dragon Knights and Goblins (neither of which even existed until they were invented for Divinity 2).
