Unless he moves the coins to another address, I don't believe him.
You don't have to believe nobody because it's the genesis block address and only satoshi is the one who's known to have access on it but we don't even know where he is or might be dead and unlikely to come back.
When I look at Explorer, that address never sent any btc yet (only received), is it possible Satoshi forgot the private key?
Most likely and that's what everyone is believing. So satoshi played it really well and proven one attribute of bitcoin for being anonymous whilst him, pseudonymous. That address is unlikely going to send any Bitcoin for what the most of us think that it's totally lost forever.
It even came from him with the quote at the first post about lost Bitcoins forever and it's probably that he did it on a purpose. So, if there are more people sending BTC on that address, it's like the burn address that satoshi has assigned but there are other addresses that have served the same purpose.