Retail buying gold and banks selling them to buy crypto.
Gold is useless for banks in the new financial system gold is not corruption free like btc or crypto there is no actual track of gold how much gold is minted and controlled so bankers don't need gold they need btc and crypto.
Retail buying gold so bankers selling gold and buying crypto.
The biggest secret is that banks buying crypto a lot not gold the gold is for retail buyers.
I wish you can share the source of this information because this is either a poor speculationnor a lie, that's my take on it. If Banks are selling their Gold to buy crypto, we would have seen heavy demand on Bitcoin in particular or even broke the all time high by now but there is no claim of Bitcoin reducing from any centralized exchange, in addition Gold has just reach its all time high some months ago, only retail buyers can't move the historic price of Gold to a new all time high.
It possible that some Banks are buying Bitcoin but selling Gold? No or perhaps there is a particular Bank that sold the Gold reserve to buy crypto buy not Banks. If federal reserve are selling and buying crypto or buy Bitcoin since the president believes in crypto, then others might consider but if they don't, then everything becomes speculation and not really the thing happening behind the scene of the banking system.