Looking for archived screenies now, but here's what I distinctly remember about the POR leak:
-PORTRAITOFRUIN posted it around August 2006, four months before the game came out
-she spoiled the game's major revelations in her post: Wind is Eric, Stella and Loretta are actually his daughters, and the Vampire Killer isn't at full power in Jonathan's hands because he needs a Lecarde to help him unlock it
-she indeed showed footage of the game beyond what we had already seen from official trailers and gameplay
I'll admit the first two revelations could have been lucky guesses, but the third was so out there that it couldn't possibly be one. That, the dumped OST (which I only now remembered, thank you Foffy), the footage, and all of the above being completely spot-on when the game came out confirmed her legitimacy. So if she made a claim about "two 1999 games", her track record meant you could take that claim with more grains of salt than other purported leakers.
So this was around the time that Konami was shopping around for what to do with the series, and it's possible that if they *were* planning, as a last ditch effort to increase the brand's buzz, a 1999 game or something, (two games seems odd) if there was anything planned there, it was probably canned when Konami picked Mercurysteam and Konami Europe for the next Castlevania game.
Even now, I think two 1999 games was odd as well. I don't personally remember her saying anything about Julius and Alucard though, or that one would be for DS and the other for PS2. I always assumed those were educated guesses by other fans derived from "Two 1999 games. That is all."
But let's say "Julius/Alucard for DS/PS2" was true too. What happened then? Maybe IGA was throwing barebones game ideas at the wall, aka Konami, to see which one stuck. That would line up with his style; he's said that for Castlevania, he prefers to make the game and its mechanics first then craft a story around it, not the other way around.
Konami then showed interest in two ideas: a 2D game following their handheld endeavors since 2001 and a 3D game following LOI and COD. IGA figured that the Demon Castle War was too big for just one game, so he planned to use those two games to tell the final chapter of the Dracula saga. This could also have been fueled by the winds starting to change at Konami, and perhaps IGA figured he'd better tell one last story over two games before he either bowed out and/or the execs moved Castlevania in a new direction. This (completely theoretical) early plan is what PORTRAITOFRUIN heard and leaked before Konami brought us to where we are now.
Yeah... two 1999 games woulda been weird. But it could also have been fun and given us fans closure for the IGA era, if nothing else.
Off topic but somewhat related, I also remember an “insider” that leaked boss info on the yet-to-be-announced Order of Ecclesia. He asked for help on translating the boss crab creature’s English name on the GameFAQs forums. He disappeared soon after, many of us were skeptical & thought the screenshot he provided was a hoax, but history proved that he was in fact legitimate. His identity, along with PORTRAITofRUIN, remain a mystery
I remember him too. Given why and what he posted, he could've been involved in localizing the game for the US. He disappeared after user Semianonymous emailed the screenshots to Konami and asked if they were legit. People joked that Semianonymous had cost the poster his job, moreso after those screens proved real.