Originally Posted by
Preypacer
I think it's based on the chat server being separate from the zone servers, so while one is loading new data, the other is continuing to stream chat text to you. Or, perhaps, it queues any chat text and then updates it once the zone loading is complete.
When I play Age of Conan, which also uses zones, I can zone into a new area and when I load into the new one, all the discussion that took place while I was zoning will be updated in the chat log. I won't have missed a thing.