Some of them have migrated. I imagine others are taking more of a "wait-and-see" approach. For what it's worth, Codeberg is quite a major contributor to Gitea

Some of them have migrated. I imagine others are taking more of a "wait-and-see" approach. For what it's worth, Codeberg is quite a major contributor to Gitea as well as the biggest public instance, and they are supporting the fork and will be switching over after the first stable release.