I feel like I argued against this at some point, but at the time I think that I thought the distance was half what actually is...
In any case, with a larger number of active AVs these days I am noticing there is a lot of flying above messaging. The vertical range for this feedback is very long, longer than any other visual or sound feedback as far as I know. ~5-10 messages in a room depending on if a vehicle is flying over or flying in gets a little excessive at times, and two AVs flying nearby can be positively screen filling.
I feel like even halving the broadcast range on this feedback wouldn't be any kind of major advantage to their visibility and would cut down significantly on the spam.