I'm on the fence about Black Metal. There isn't enough legit and explicitly LHP/Satanic bands out there for me to be convinced how real the connection really is. Though in some ways it's better than the HorrorCore (rap) Satanic stuff I've heard. With some of the horrorcore I can tell they know of the real deal.
An example would be the owner of Serial Killin' records, SickTanick. He mentions Alister Crowley, Anton LaVey, and he has a recording of Crowley, parts of Satanic rituals in his songs, one song that essentially quotes an invocation to destruction, and mentions of other ideas that he had to of at least read some stuff up on about it. But it's also filled with stereotyped blood stuff and violence and genocidal rants about how evil Christians are.
As for Black Metal, I got a few bands on my MP3 but even like Dimmu Borgir is not explict enough. I know that Archeon was founded by a CoS member and seems really legit, but the generalness of those types of band is kind of disappointing for me as I essentially want songs that can express not just the emotion, but some type of philosphy behind it. Generally I have noticed that Metal is not the best platform for this, and it can take a whole song to express an idea such as "the war in Iraq is terrible and was for Bush's gain", where-as in rap you can express that in two or three lines. I think it's just how the lyrics of the genres are built, but meh.
Anyway I don't think that there is implied to be a link between LHP and Black Metal, but there is a very strong overlay. But hell, there is even "white metal" bands that are Christian but try to use Black Metal sounds. An example of that would be Demon Slayer after they left the Nu-Metal genre.
Personally though, a rap-metal or alternative metal mix for a Satanic band would be my dream idea of a band. Best of both worlds. Then again I like alternative metal/rock that experiments with other elements. Incoherent rants are a bonus too. Otep and System of a Down being two examples of the kind of style I am talking about.
But again, while there is a very strong overlay between Black Metal and Satanic themes, I don't think that most "Satanic" Black Metal bands really know anything about Satanism or even the LHP.