I thought I'd necro/resurrect this thread in true Vampire fashion.

I've been doing a lot of reading on WH Vampires since the Total War Warhammer series moving East to Cathay has sparked a lot of discussions on possible expansion of existing factions and reintroducing long forgotten ones.

As far as Vampires and their bloodline founders, I've found evidence to the following:

Neferata, W'soran, Ushoran, Abhorash remains unchanged. They're still the founders of the Lahmian, Necrarch, Strigoi and Blood Dragon bloodlines respectively.
Vashanesh is still understood to be Vlad von Carstein, founder of the von Carstein bloodline.

As others have mentioned. Harakhte and Maatmesses were said (in Liber Necris and Night's Dark Masters) to be the other members of the original cabal and possible bloodline founders that went of East after the fall of Lahmia.
Not sure if it's to do with copyright issues or what, but as others noted, both Harakhte and Maatmesses seem to have been "replaced" with Ankhat and Zurhas with Naaima being added as an additional member of the original cabal.

Harakhte seem to have been replaced by Ankhat as the Grand Vizier of Lahmia by Mike Lee for [Rise of Nagash: Nagash The Unbroken](2010) and Josh Reynolds continued using Ankhat in [Blood of Nagash: Master of Death](2013).
Interestingly Ankhat talked about "living up to his family name" in [Rise of Nagash: Nagash The Unbroken] perhaps this was a nod to Harakhte being his title/family name. Ankhat in [Blood of Nagash: Master of Death] was explicitly mentioned as the one who went and worked for Cathay after the fall of Lahmia, but got chased out again after being revealed as a Vampire, but it's possible he sired a bloodline in Cathay before he left, or somehow snuck back in and ingratiated himself with the Cathayan court again and sired the Sorcerer Eunuch Vampires.

Maatmeses could have possibly been replaced with Zurhas, again by Mike Lee for [Rise of Nagash: Nagash The Unbroken]. It was rather unclear what Zurhas' job was in Neferata's court. He was mentioned as gambling addict. So he could have been the corrupt Chief Judge like Maatmeses was supposed to have been. Although the discription of Zurhas' vampire transformation has him looking sickly thin with rodent like features, puts me in mind of a Nosferatu, which is a departure from Maatmeses being fat. What was also mentioned in [Rise of Nagash: Nagash Immortal] was that Zurhas seem to have given up his vices when Ankhat last saw him in Lahmia before they all left. So it's possible Zurhas started to take his job seriously, but it was too late since Lamhia was gone, he went mad and started a rogue court in the jungles of Ind and the Southlands with blood priest as judge, jury and executionors. It would be cool to have fat vampires for a change, so maybe Zurhas/Maatmeses' bloodline could be afflicted with extreme metabolism, causing them to yoyo between being thin like a Nosferatu to being fat after they've gauged themselves on victims they've judged unworthy of life.

Naaima is also now a possible bloodline founder, but no story ever mentioned or hinted at her having sired a bloodline.
Prince Xian Ha Feng wasn't a member of the vampire cabal. he was given small vials of Neferata's blood to drink and to take back to Cathay, not the cursed exilir itself. So at best he's a Lahmian, not a bloodline founder, or at worse he extended his live a bit, but became Neferata's thrall, not even a full Lahmian Vampire since Neferata didn't give him the blood kiss.