According to WordPress.org:
WordPress 5.9, Joséphine is named in honor of acclaimed international jazz singer Joséphine Baker. This latest, most versatile WordPress release is here.
As a lifelong civil rights campaigner, Joséphine Baker believed that all people could live in harmony together, just as different instruments in a jazz band blend together to make a whole piece. Turn on a playlist from your favorite music service and enjoy her famous renditions of “You are the greatest love”, “Sans Amour”, and “Love is a Dreamer” as you discover all the features of this brand-new WordPress release.