Here's the quote regarding controller support for DOS2:
Of course, you released the Enhanced Edition on consoles as well and I bet there are a lot of console gamers interested in Divinity: Original Sin 2. Is that something you’ll be making after the PC launch?
Yes, we’re focusing on releasing on PC first. And that means making it run on PC, making the user interface for mouse & keyboard…Once we’ve done that and we’re happy with the game, we’ll start looking at user interfaces that support a controller, be it for PlayStation or Xbox or if only to be able to add controller support on PC.
We’ll look into consoles after the game is done.
So there won’t be controller support on PC at first?
Not initially, no.
tl;dr no controller support for EA, may be added in once the game is 1.0.