In my opinion, he didn't plan to leave bitcoin in the beginning, based on this quote:
It would have been nice to get this attention in any other context. WikiLeaks has kicked the hornet's nest, and the swarm is headed towards us.
So the way I interpret it, perhaps he thinks of slowing down first or totally leaving the project in which he did. And Satoshi could have been right, because months after,
Gavin will visit the CIA. I think the same, especially since he disappeared in a hurry and basically mid conversation. There was no slow exit or a exit when the project bitcoin was finished. He was one day there, writing in this forum about stuff that has to be done and then gone the next day. To me it seems like it was at least to dangerous for him to use the account satoshi for any more time.
My guess was always that if he did not die, then he would have registered another account.