Traffic. What of course you are leaving out is how the system has worked in practice for over 50 years.
In the USA the Unicom operator gives any information that may be useful re improving safety.
At most of our airports there is no one on the ground listening on the CTAF to report even if the voice modulation on the transmitter has failed.
It has worked so well in the USA and Canada that there are no plans to make the regulations more prescriptive.
For 25 years I have been working on copying this system- one day I will get success as new blood comes into the industry and the concrete minded ones die out. You watch!