Ever since Marvel Studios regained the rights to Blade, there have been some pretty stubborn rumours that we're going to see either a movie or a Netflix show starring the Daywalker (possibly even with Wesley Snipes involved) the question of HOW that could happen has been loud and proud.
If vampires were to be introduced to the existing MCU, we'd need a serious deviation from the current spirit of the franchise, which has mostly avoided supernatural elements (magic aside). And you'd think they might have made some sort of appearance by now if they already existed?
The multiverse could offer an answer, of course, and with Ant-Man And The Wasp apparently opening up those possibilities, that answer may come soon. But as one poster on Reddit has already noticed, there is already a bit of establishing work for vampires in the MCU thanks to Thor: Ragnarok.
The Redditor pointed out the What We Do In The Shadows Easter Egg gag that saw Korg pick up the tri-staked fork and said it would only be "useful against three vampires standing in close proximity" and suggested that it could mean something far more important than anyone's noticed.
"Firstly, Korg is not from Earth and knows nothing about Earth or its culture. The ending of the film shows this directly where Thor talks about going to Earth and Korg hasn’t heard of the planet or anything about it. Now, one could say that vampire fiction found its way to Sakaar and Korg really liked it, but that doesn’t make sense. Korg mentions them casually, which means he assumes Thor knows about vampires... Secondly, Thor doesn’t really react to the comment, but he does hear it and acknowledge it. This means Thor did indeed know what vampires were and wasn’t surprised that Korg also knew. If Thor simply had read up on them while acclimating to Earth culture, he would have been surprised that Korg knew about them. His casual acceptance of Korg’s knowledge means Thor is aware of how widespread vampires are. It also shows that he agrees on how wooden stakes would work on them."
Simple but effective explanation there, but what does it mean?
"The only conclusion is that Thor has battled them in the past in multiple locations. Thor had read up on Dark Elves but didn’t think they were real until he met them, so if he had merely read about them from Asgardian history books he would have been surprised to learn they were also real."
So, vampires are basically aliens, then? That would solve the whole supernatural issue in the MCU if Marvel ever wanted to bring in Blade and not have him as a stand-alone so he could interact with other established characters.
If vampires are simply empowered aliens the same way Asgardian "gods" are simply explained by alien origins, then that gives Marvel the backstory to suggest how they came to Earth in the first place. And maybe we could see them established as a threat to cosmic MCU characters first before Blade makes his debut?
It might sound outlandish, but there are very few brushstrokes in MCU movies that aren't intended precisely. So it might be worth considering.