I would think that is only acceptable if it's a police-escorted convoy. Otherwise, anyone could simply abuse it. I frequently see police-escorted convoys with hazard lights on.

I've been in a police escorted convoy in Thailand (club drives from Malaysia, escorted on Thai-side by Thai tourist police) where the convoy vehicles were asked by the Thai police to turn on the hazard lights as we were supposed to follow the police cars and not stop at red lights.