Hopefully for Larian's next game they will have the resources to finish plenty of time before release. That would at least make a non-Steam retail release more feasible, though I don't know if it would be any more likely.
When trying to get as much as possible in the game right up until the release (including delaying the release 10 days to finish adding the voice work being done), a non-Steam disk version wouldn't necessarily be updated, so could have features lacking. There would also be triple the amount of QA for the release (testing the disk installer and game, the digital install and game, and then the disk version patch to bring it up to par with the download version), as well as possible additional complications supporting the original disk save format for any future updates.
