Interesting discussion. Didn't realize the "looking for volunteers" message came from higher powers than the GA.
To be clear: If the sign is ON, we know they either need volunteers or don't need volunteers. If your a bump runner, you probably approach the GA regardless. If the sign is OFF, there is a good chance they don't need volunteers (a few exceptions though) because its programmed to turn on when booked (over) to a certain level. In most circumstances that number would stay the same or drop (ie: misconnects), and therefore not prompt the volunteer signage.
Is that a good interpretation?