I don't believe that the 1 million bitcoins that Satoshi is holding will be lost forever because we can't tell if Satoshi have intentions of gaining access to his wallets in the future so it will be wrong for us to assume that his bitcoins will not be in circulation, after all even in Fiats, there are people who kept a huge amount of Fiat in secret places and it got rotten and destroyed in the long term but the reason why i like bitcoin is that even if you lost access to your wallet the amount will still be visible in the blockchain which still helps to strengthen the network as long as they are still intact without being traded or converted.