Central banks of various countries are using Bitcoin as a transaction and as a holding. This is definitely a positive aspect for Bitcoin, because if central banks support Bitcoin, the people of that country will be attracted to Bitcoin holding. Various officials including the government will also be involved in this Bitcoin holding, they will grasp Bitcoin more.
Which Central Banks are you referring to?
Apart of the Czech Central Bank, which bough a scrap of Bitcoin, most likely a test, I am not aware of other CB’s holding Bitcoin, or any other digital asset (namely, schitcoin).
Look, Taiwan central bank supports Bitcoin, but gradually the central banks of all countries that have adopted Bitcoin as a strategic reserve will support it. Because the Czech central bank has supported Bitcoin.