This is a very plausible theory. An analogous phenomenon happens in the world of memes, where some ideas produce "phenotypes" that wipe out other, competing ideas. c.f. Tienanmen Square in China or the Nag Hamadi scrolls.
I have, I'm interested in memes as Dawkins defined them then. I've also read many translations of Nag Hamadi scrolls, so your example sparked my curiosity. Perhaps I need to re-read The Selfish Gene, it's been more than a decade now.
Edit: with reflection I think I understand what you were getting at, that the memes contained in the Nag Hamadi corpus had been successfully suppressed by their memetic cousins which for whatever reason came to be the dominant 'version' of that information, until an accident of history reintroduced the different versions that had been all but extincted in the memepool.
