Originally Posted by
Steve M
It's the Captain's discretion, but my understanding and belief is that in such a situation, an announcement to passengers is warranted in such a situation, if only to the effect of "You may see emergency equipment meeting our aircraft upon landing. No need to worry - they are there out of an abundance of caution" rather than leaving passengers wonder why fire trucks with their emergency lights on are pacing the aircraft on the adjacent taxiway.
Yeah I'd like to know before landing, but there's no need to tell the pax when you're still an hour out. Which is when the mayday was called here.