As the Cabin Supervisor, I would consider it as one of my duties to relay information of the mood in the cabin to the Captain, and to suggest communication if I considered it appropriate. In the event that the Flight Crew were too busy, I would seek permission to make a "holding" PA myself, pending a later, more authoritative PA from the Captain. In short, Cabin Crew are part of the team, working in the cabin on behalf of the Captain, and he/she relies on them to handle some aspects of the communication/people duties on his/her behalf.
- P.S. This is not a criticsm of the crew involved: I was not there and cannot know - this is merely an observation, intended to clarify a question.
- P.P.S. I have been flying long enough to know when is not an appropriate time to be troubling busy Flight Crew with cabin communication issues.
- P.P.P.S. This is not an attempt to erode the authority of the Captain, or to exaggerate the role and importance of the Cabin Team