My guess is that sending out DRM-free DVDs separately may be simpler for Larian, rather than assembling a separate set of DRM-free CE sets. But if so, they could have done a better job of letting backers know.
Probably so, though to be fair, I'm sure they're still a bit overwhelmed from the launch. They pushed themselves far too hard to get it out on the 30th. No doubt some things got overlooked on accident.