That's just a random person repeating familiar speculation. Len Sassaman has been named before because he's a well-known cyberpunk cryptographer. It's still unlikely, if only because Satoshi kept communicating privately after Len died.
Satoshi's coding and communication style is that of an older Windows software engineer without a PhD, specialized in networks rather than cryptography. He was competent, but not a genius besides one breakthrough idea. (For example, the code is not well-organized and he hadn't heard of Wei Dai until Adam Back mentioned him.) Which makes it unlikely that he's anyone we'd heard of before.