LRH. He actually did mention that it was still garbled when they were told that masks were no longer required. As I mentioned, he's a seasoned traveller, ex AN CSO & Flight Service officer and not prone to exagerration.
does anything display on the pax screens
When the crewed informed the punters that they were diverting, they didn't mention a destination however, the chap next to my BIL had the moving map screen on & it showed them turning to MNL. So, I'd say that there was no specific on screen warnings but you raise a good point. If it's difficult to hear or see in an emergency, that would be an excellent way to communicate to the great unwashed!