For US Carriers:
§121.571 Briefing passengers before takeoff. (the thinned down version)
(a) Each certificate holder operating a passenger-carrying airplane shall insure that all passengers are orally briefed by the appropriate crewmember as follows:
(1) Before each takeoff, on each of the following:
(i) Smoking.
(ii) The location of emergency exits.
(iii) The use of safety belts,
(b) Each certificate holder must carry on each passenger-carrying airplane, in convenient locations for use of each passenger, printed cards supplementing the oral briefing. Each card must contain information pertinent only to the type and model of airplane used for that flight, including—
(1) Diagrams of, and methods of operating, the emergency exits;
(2) Other instructions necessary for use of emergency equipment; and
(3) No later than June 12, 2005, for Domestic and Flag scheduled passenger-carrying flights, the sentence, “Final assembly of this airplane was completed in [INSERT NAME OF COUNTRY].”
So there is not a requirement to inform the SLF to leave everything behind. Airline X probably does not want to add it, because it might scare the pax to Airline Y. Not sure about other countries, but probably something along the same lines.
