It's only those covered by the long haul EBA making the PAs, which also happens to include the 767 lads flying on domestic routes seeing as they are covered by the same agreement.
I heard two last week (on separate flights), one during cruise and one just prior to disembarkation as the aerobridge was being attached. The one during cruise definitely had more people paying attention as once the seatbelt sign is off, people start focusing on getting their bags out of the overhead lockers and getting off the aircraft.