I was on a flight from HOU-ATL last week and everything looked normal for an on-time departure until the GA announced that FA (one of the two) has lost her voice and they are looking for a replacement FA. Ten minutes later they announced that the flight was cancelled because they can not find a replacement and it is against FAA rules to have an FA that can not clearly communicate directions in case of emergencies.

Delta cancelled the flight and re-routed pax, some of them next day (with hotel/food vouchers etc). Fortunately I was able to get the next (last flight of the day) flight due to my status.

I just thought it was peculiar and if others had run into similar situations that on the surface sounds silly/trivial but end up causing so much cost/trouble for all involved (pax and the airline).