That's not a gnome-session issue, and is not really a bug at all.
pulseaudio clients will autostart pulseaudio the pulseaudio daemon if
it's not running. You can disable that in the pulseaudio config.
** Package changed: gnome-session (Ubuntu) => ubuntu
** Changed in: ubuntu
Status: New =>
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Ubuntu better. This bug did not have a package associated with it, which
is important for ensuring that it gets looked at by the proper
developers. You can learn more about finding the right package at
https://wiki.ubuntu.com/Bug
