I sometimes wonder if they indeed moved on to other things or just said it to leave the project harmlessly. They could also had a disease and didn't want to reveal it. What a mystery.
I mean, sit down and think of it. During a financial crisis and out of nowhere, a stranger creates “magic internet money” by solving a problem that was considered impossible 'til that year, sees it working and disappears. Unbelievable.
Totally unlikely, but sometimes I just think of the potential chaos it would bring if suddenly Satoshi decides to login on Bitcointalk and post again(with signed proof of a Satoshi address). I would really love to hear Satoshi's opinion on Bitcoin's current state.
Not that it matters, but Satoshi's account is sort like banned to prevent anyone from logging in and bringing the potential chaos you said, however without a signed message it wouldn't.
I'm sure they'd like the Lightning Network as a concept. They did speak of the scalability issue;
The current system where every user is a network node is not the intended configuration for large scale. That would be like every Usenet user runs their own NNTP server. The design supports letting users just be users. The more burden it is to run a node, the fewer nodes there will be. Those few nodes will be big server farms. The rest will be client nodes that only do transactions and don't generate.