As reported at https://github.com/QubesOS/qubes-issues/issues/2650 by Holger Levsen.
Qubes OS version (e.g., R3.2):
Affected TemplateVMs (e.g., fedora-23, if applicable):
pulseaudio and vlc should not be installed in sys-whonix.
#2648 is the issue suggesting to split out a qubes-gui-agent-pulseaudio package out of qubes-gui-agent.
once this has been done the whonix-workstation package should depend on qubes-gui-agent-pulseaudio
and the whonix-gateway package should not (and then vlc and pulseaudio wouldnt be installed in sys-whonix.)
We need a Whonix-Workstation meta package (existing or new?) to depend on pulseaudio-qubes.