MySQL Connector/J 9.0.0 has been released.
https://dev.mysql.com/doc/relnotes/connector-j/en/news-9-0-0.html

"Synchronized blocks in the Connector/J code were replaced with ReentrantLocks. This allows carrier threads to unmount virtual threads when they are waiting on IO operations, making Connector/J virtual-thread friendly. Thanks to Bart De Neuter and Janick Reynders for contributing to this patch. (Bug #110512, Bug #35223851)"