Nah. The way I understand it, while Dragon Commander is set in the Divinity universe, it's set so far into the past of the other games that they don't really matter for reasons of plot. Maybe there'll be a bit foreshadowing here and there, but only as fanservice, I think, not integral plot elements.
The only thing from the other games that I think might show up is Bellegar. But if he does show up, you'll soon realise what his deal is.