At the moment it seems chat messages are seen only within radar distance. In Alpha, messages could be seen in the whole of QA. (Wiki still says this, but I tested it yesterday, and they aren't).
I think it is essential for new players to be able to trade their rocks, buy steel picks, and generally listen to advice from other players. They can't do any of this at the moment if they are actually picking rocks or shooting slugroaches. Why should they have to stand about in NU, just waiting?
To give a satisfactory experience to new players, and indeed players who are trying to trade with them, the chat in NU needs to cover the whole zone.
I'm beginning to see more and more green dots, but there is utter silence, no communication whatever. There is no feeling that this is a multi-player game.