The vault 2 was going to be a sequel to 'the vault'
The plot was going to be about jack trying to help Adam with his illness
Cancelled due to fact that there just could not be a sequel made from the previous video. However this does not mean there won't be any vault related videos. There could be an origin story on how Adam and Jack met
FOLLOWUP- there might be no origin story because The skin pack which contained jacks skin is not available for the Xbox one version of the game. a possible and very cheap reason for his difference would be he has a makeover in between the videos.