chat cool downs are common in some MMOs for the global channel, some even require that you use a certain item to be able to speak in global. The point being, that there are many possible solutions to manage the frequency at which these channels are being used. but again, we are getting WAY ahead of ourselves if we are already concerned about this - personally, i would be very glad to see our chat channels full of text, this will be a good indication that the game world is healthy.