It seems plausible, but all the trials will certainly not be immediately applicable to all sectors of the economy. Central banks must properly assess the results and benefits of using crypto, as well as the negative impacts of using it before governments can actually issue regulations.
I think the central bank only uses technology in cryptocurrency, the technology used by bitcoin has also been very strong until now and can be combined with the technology used by banks, so it is impossible to create their own cryptocurrency because some governments still do not provide legality for transactions cryptocurrency.