I can confirm that the beeps only happen when shutting directly from within a GNOME session; shutting down from KDE, or by logging out from the GNOME session and then shutting down from GDM, don't cause any beeps (not even one).
I can confirm that the beeps only happen when shutting directly from within a GNOME session; shutting down from KDE, or by logging out from the GNOME session and then shutting down from GDM, don't cause any beeps (not even one).