Thanks for all the replies, everyone. Because the following post is already very long I didn't end up replying to most of the points people brought up. However, I'll make sure to do so later.
Additionally from what I've read it's always seemed to be SCIV was intended as a re telling of CV in Japan, but the US version read more as a sequel to CVII.
I think this is has been the consensus for quite a while, isn't? The Japanese version was always a "remake" and the overseas version took creative liberaties and made it a sequel. However, in cases like this it's important to reexamine what we already know. For example, it's important to consider this theory has never been officially confirmed by anyone involved with the series. I suppose there's Cox who considered the game a remake, but I wouldn't consider his view to have any more weight than the average fan.
The fact that the game is called "Akumajou Dracula" might indicate it has some relation the the original Famicom game, but this fact by itself doesn't really say much. First of all, it happens to be both the name of the first game and the overall name for the series after all.
Furthermore, one of the people involved with Haunted Castle denied it's any kind of remake of the original Famicom game, yet in Japan, the title of the game is still Akumajou Dracula. Meaning there is no "rule" that when a game is called Akumajou Dracula this makes it a remake of the first game. There could be all kinds of reasons why the title was chosen. The title may not necessarily imply a relation with another game, but could simply be a busines decesion, like brand recognition. Or perhaps it might indicidate the game is a fresh start. You can't just assume the title implies something specific if this isn't confirmed by the developers themselves.
And last but not least, there's no contemporary official material that outright refers to Super Castlevania IV as a remake. For example, that booklet that came with that Castlevania Best Music Collections Box says the game uses the story from the Famicom game, but "the game's contents are a completely new work". The game is only refered to as a remake by the fanbase. Also, the producer of the game's director himselves denies the game was developed as a full fledged remake. It's hardly a clear-cut case.
About the assumption about the localizers going rogue and making SCIV a sequel, do we really know this for sure? After all, we don't know anything about Konami America and Konami Japan communicated with each other. We don't have any evidence about how things went down.
This is just me playing Devil's advocate, so you could say: "Well, where's the evidence for your theory then?" And the truth would be that I can't provide much of it. However, I found a really interesting preview from the game back from a 1991 issue of Electronic Gaming Monthly. I found this after I had already developed my theory, and I was suprised and how much it lined up with what I had came up with it.
Note how it establishes the following things:
- Simon defeated Dracula 100 years prior to the beginning of the game.
- Now the people of Transylvania are looking for a "new and more powerful Belmont".
- The protagonist of the game is refered to as Simon Belmont.
So, assuming the writer isn't simply condradicting himself, this strongly backs up my theory. Of course, I know it isn't that simple. We would also have to consider that this is just one specific preview and perhaps the writer was just making it up. However, when looking at other previews from that period, I couldn't find another one saying the same thing, but what all these articles share in common is that they use the same rhetoric of Super Castlevania IV being a sequel.
They do go about this in different ways. Aside from the preview I posted, there are two other types. The first kind of article describes the game as a sequel but does so in a very generic and un-specific fashion. "Simon Belmont is back!", etc. The second type seems to describe the game as a direct sequel featuring the same Simon Belmont as before.
What I personally think may have happend is that the journalists who wrote these articles may have gotten the information from Konami that the game was a sequel to Simon's Quest and that the protagonist was a "new" Simon Belmont, but then this information may have gotten muddled along the way. Perhaps the English intro of the game adding the bit about Simon "once again" going up against Dracula may have been some misguided way of further making clear the game was a sequel?
But that's just speculation, so let stick to the facts. One could say: "So what? The information is from an English video game magazine, which weren't always reliable back then". So I also decided to look into what Japanese had to say about the game. I did find a magazine which contained a preview of the game (Weekly Famicom News) which I already
posted on the Castlevania wiki. This isn't in any of the scans but in the table of contents it says: "シモン伝説再び!" (The Legend of Simon returns!). As for the conents of the article, it doesn't really say anything about how exactly it relates to previous entries, just that it's the newest game in the series. It also doesn't say anything about it it being a remake or something. Anyway, there's at least one more magazine I want to check out, so I'll let you guys know if it says anything interesting.