The inventor of Bitcoin never posted anything to BitcoinTalk, so BitcoinTalk is not part of Bitcoin's history!
I'll have to disagree with you here. Bitcoin is bigger than Satoshi Nakamoto, and Bitcoin's history isn't limited to a certain domain name.
Of course Bitcointalk is part of Bitcoin's history!
I'd definitely agree with that. My knowledge of bitcoin history is pretty weak--I'm still reading
Digital Gold but can't seem to get past the Mt. Gox debacle just because I haven't had a lot of time for recreational reading. In that book, there was mention of a forum on which Satoshi posted early on, but I can't recall if it was named as bitcointalk or not. If what OP says is true, it probably wasn't.
But saying this forum isn't a big part of bitcoin's history is just plain wrong. Even if Satoshi didn't found it, it's been around since the beginning and some of the biggest personalities who've come along have posted here, even Satoshi Nakamoto.
I'm curious as to OP's motivation here as well.