I don't know what the state of the game will be on release. I can't confirm that it'll be incomplete, I did not watch the livestream for more than a few minutes, and even then it was only when the editor was up. So take my comments as hearsay.
I believe that Larian has no choice but to release it, for financial or logistics or contractual reasons, it is now too late to delay the game's release.
Well from the last vid it looks like the game is already boxed up and ready to drop in the mail. So the only things they could add at 'launch' would be a First Day Patch, which isn't that uncommon these days. In fact anything they are working on now (and it looked like they are still working) obviously isn't going to get into the boxes that are ready to ship. Day One Patch.