Satoshi stepped away from Bitcoin in 2010 and handed over the project to the maintainers.

Len started posting about Bitcoin in 2010 (post Satoshi handing the project over).

It seems to me, if Len was Satoshi, he grew distant from the project. Maybe it wasn't the cypherpunk utopia he envisioned. Maybe the wikileaks and silkroad issues weren't what he wanted to enable. Perhaps he wanted to distance himself further from the project.

He was also depressed at that time.

My understanding is around the time SN left correlated to around the time Len’s mental health escalated. That noted, RIP/don’t mean to crassly speculate about what sounded like a talented and difficult life.