I used this procedure https://community.home-assistant.io/t/absolute-beginners-guide-to-installing-ha-on-intel-nuc-using-docker/98412 when i setup my NUC for HA. I’m at Ubuntu 18.04, HA 106.5, and 208 supervisor. All is well. A new container was created for hassio_audio. It’s likely a permissions issue people are experiencing when the update attempts to create the new audio container.
I ignored the manual 207 Supervisor update, and let the update occur automatically with the HA update to 106.5.