(There is a newly recommended package for udev to discover available sinks in Pulseaudio 9 and I didn't have the package installed.)
Mike Hommey asks "Should it only be recommended, though?" The answer is yes. While I can only guess at the reasons pulseaudio has been decoupled from a hard dependency upon udev the change is clearly intentional (and correctly implemented). Recommended packages are installed by default. Only an expert user will disable the automatic installation of recommended packages. Expert users should know what they're doing and we both made a mistake. Regards, Adam
