I thought the retail version just had a disk check on install, and only the download releases used online activation.
Due to some "divine" coincidence. I had to install DKS because there is this... 1.2 patch for Skyrim *cough* that *cough* made me *ahem* look back at DKS and other games.
For Divinity 2 DKS PC AUS, after DVD install, when you launch the game it asks for the "key" then connects for activation. From then on forward, no DVD required.
IIRC when uninstalled it's supposed to deactivate.
Much like Sacred 2 so the ritual is familiar with me.