Perhaps what is being suggested is more along the lines of:
Global Chat Channels

Just like linkshells, but you do not need to equip a linkshell to use it (and therefore do not need to be a member).
There would be more than one chat channel you can join, for example:
/chat "Conjurer" <message>
/chat "Goldsmith" <message>
/chat "ExpParty" <message>
/chat "Primals" <message>

Everyone could tune into which channel they want to listen/speak on.
Would make it easy for many people to talk with each other based on a specific topic.
Could blacklist people who spam or are annoying.