First off: Respectfully, you can fuck off with your nonsense. We all have a mind. Which gives us the right to think and believe as we wish. Whether anyone else thinks you're right or wrong. It's your mind. Not their's.
To answer your quick and baited question, I do believe it is. Same as I believe fucking a zombie is. But has that stopped me from fucking them in a game? Or playing as one in a game? No. If BHG would like to have some choice words for me, that's cool. As I said, everyone can believe as they want.
It is a metaphysics question. There is a diversity of opinions on it and frankly some are less valid and sound than others.
I find the logic "We all have a mind- which gives us the right to think and believe as we wish" a tiny bit disingenuous in regards to refuting any specific answer.
Yeah, you have the right to believe whatever you want- but that does not make your belief logical a priori. You can "believe with your mind" a rock is a magical healing crystal all you want, but that doesn't make your belief reasonable. Believe what you want, but belief is not fact and the laws of nature do not bend to belief they are defined by empirical evidence.
That said...this particular question doesn't have a super-clear answer b/c there is understandably a lot of mystery surrounding death.
In the case of the question, "what makes something necrophilia?" it kinda boils down to, "when is a sapient being dead?"
It becomes a ship of Theseus question. What parts can you take away from a sapient being without them becoming dead?
A lot of people would draw the line at being brain-dead. And this is the definition of "dead" used by the medical community. Even if the rest of the body is alive. If we use this definition and extrapolate it onto necrophilia, I don't think you can call sapient creatures necrophilia.
If you have more of a dualism view like the early Christian philosophers, then its like....half necrophilia.
If you think someone is dead if their body dies, even if their mind is alive. Then yeah it is necrophilia. I personally don't find this definition that persuasive as long as the mind is still attached to the body. Back to ship of Theseus; I don't think anyone is gonna say you are dead if you lose your arms and your legs...but with this definition you are partially dead.....so is it partially necrophilia? How much of your body can you lose before you are actually dead??? Does Nixon's head in a vat in futurama count as dead? Am I dead if I lose my pinky finger? ect ect.
Could also just boil down to symantics; If your defniition of necrophilia is "attraction to dead body" instead of "full dead." Then yeah, Vamps ect is necrophlia. The term is kinda loosey goosey on that...prob b/c it isn't something that is ever real life applicable so no one has had to nail down this particular nuance of that definition.