The symptoms will look like this:

Error: Failed preparing container for start: Load go-lxc struct: Cannot apply limits.disk.priority as blkio.weight cgroup controller is missing
Try `lxc info --show-log local:gnome-test` for more info
launch fail

The upstream issue related to this is: https://github.com/lxc/lxd/issues/7420

I have left a comment. I don't think the default behavior in this case – of causing the container launch to fail – is a wise way to handle this.