If he is as smart as people claim to be:
1) Wouldn't ever happen (he claimed himself that people should never delete wallets)
2) Gets countered by point 1)
3) That's not a logical thing at all.
If he really is as smart as people think, he would never touch an altcoin.
While I understand that starters or backers of altcoin would like to spread this idea..it is completely unbelievable.
He knew that if bitcoin was not to be seen as 'his' personal project and truly become a global currency he would have to back off and also limit his own amount of currency.
If he for example owned 50% of all coins.. people found find it strongly unfair and feel they were working for him. To make the currency successful he would need people to take ownership of the idea.
So there is a very very good reason he backed off.
But I think he is still in btc. Perhaps even fully still.