clevis and tang do currently work seamlessly on Debian and Ubuntu using initramfs-tools. So while the initramfs-tools/dracut discussion is valid, it seems mostly orthogonal to this topic.
I was unaware that they no longer depended on Dracut and now support initramfs-tools, which also seem to be the earliest clevis version that got packaged in Debian. That makes the initramfs-tools/dracut distinction a historical aspect of the project.