The last G&K Civ was revealed 6 weeks before the US release date. We're now about 8 weeks away from BNW's release date and we still don't know 4 of the 9 Civs. Is it any wonder some of us are getting impatient?
ETA: to be honest, the persistence of things such as placeholder icons and music this close to release is making me wonder if it'll be released on schedule. Perhaps we haven't seen any more Civs because they're still working on them...
The footage in the video with placeholders is obviously an older build than the screenshots released thus far. These featurettes have been long in planning and execution, its not something they've just thrown together last week.