It's already been almost a month since The Bank for International Settlements (BIS) decision that Central Banks can hold up to 2% came into effect under their "Prudential treatment of cryptoasset exposures".
BIS initially was planning for a 1%, but when Central Banks asked for 5%, they proposed a 2% as a compromise.
This news is not new, it has been announced since 2022 and according to the news BIS allows banks to hold 2% of their reserves, not just the central bank and the central bank does not require 5%. Additionally, BIS allows banks to hold cryptocurrencies but whether or not to hold bitcoin/crypto is up to the individual bank to decide. BIS has no authority to intervene or require banks to hold bitcoin and unfortunately so far: the US Central Bank (Fed) has stated that it has no intention of adding bitcoin/cryptocurrencies to its reserves. Similarly, the European Central Bank (ECB) also made a similar statement, bitcoin does not qualify for inclusion in reserve assets.
Central banks are still very cautious about crypto, they are not as crypto friendly as you say.
https://www.investing.com/news/cryptocurrency-news/bis-allows-banks-to-hold-2-of-their-reserves-in-cryptocurrencies-2966647