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.
I doubt this because regulations is still highily invoke where governments are still striving on taking control of the decentralized finance and by the intention and cryptographic program of Bitcoin by Satoshi, the governments will be doomed to compromise it decentralized potential so I wonder how banks will decline from buying treasures as golden which they are in control of than leveraging of selling it golds to buying of Bitcoin for reserve.
You can just say they are alternating (buying more of Bitcoin or crypto for the reserve while still holding on gold).
The reason of the government having the interests on Bitcoin as part of the hedge for the store of national reserves is just for the sake of the global markets influence of Bitcoin and since the US has taken the top lead, other countries foresees the opportunity as admiration to also follow suits while the Centralized treasury commodity as gold remains a primary treasure of their national reserve.
Perhaps most of the top most leading crypto reserve countries like the US has only acquired the value of the Bitcoin holding on the seizure based on illegal transactions and they never bought with their own money talk more of selling their golds to buy Bitcoin.