I realise this is a stretch but with how we have different stormcast chambers and fire slayer lodges, what are the chances they reintroduce the vampire bloodlines. It would be great to have the ability to tie in some units from other Death battle tomes, some FEC ghouls for a strigoi bloodline, some spirit hosts or a knight of shrouds helping out the Von Carsteins.
It probably will not be the case but it is an exciting thought.