James 540;
When Original Sin was first mentioned, the few things that were known (RPG, set in Rivellon, would be able to defeat the main bad guy at the end) matched what was expected for Divinity 3, so most people made that assumption.


EinTroll;
They can, but Divinity 3 will be focused on the final confrontation between good and evil (at least for this particular attempt by the Lord of Chaos to return to Rivellon), and there are lots of other things that could be done with dragon knights.