User blog comment:Blood Reaper/Skyrim Dawnguard Trailer/@comment-4976111-20120531192905/@comment-68.227.12.98-20120531224613

I think that they didn't do it intentionally, I believe that they only kept Vampirism as a fan service. But, after the game jam video they decided they needed to flesh out the story for the vampires and make them equals to the werewolves in game.