It does not seem to me that we can avoid mass outflows of BTC from spot ETFs at some point when investors estimate that the bull run is at its peak or that it has ended and that the time for price correction is coming. I think that is far more likely than Satoshi (whoever he is) putting all his coins up for sale at once - and just moving those coins from any of the earliest blocks would cause panic and a drop in the price of BTC.
FOMO buys and PANIC sales are all emotional and psychological made but it needs more time to warm up the market, trigger FOMO and make all time high than time to trigger panic in the market. Panic sales can force the price falls quickly but fortunately, in the market distribution phase is long enough for us to exit the market if we want. We can miss ATH or around it for our exits, but with a bounce for a double top, we can have second chance for our exits.
Bitcoin Spot ETFs buy and sell on behalf of their customers and not all of them are long term holders so if they have buys, they will also have sales.
In other words, I think that Satoshi cannot (even if he wants to) do something with these coins, while on the other hand, accumulation through spot ETFs is without a doubt a double-edged sword.
Let money to be controlled by two third-party entities, Bitcoin Spot ETF and its custodian, is actually a double-edged sword.