Ok. Further thought: I think since there is already some relationship between the notification thread and the chat itself via the "View/Join This Chat" link in the message, there needs to be a bit more coordination. Specifically:
After a chat has been closed, clicking on that link takes the user to the open chat list. I think it should instead (or in addition) respond that the clicked-on chat has been closed.
Taking this a step further, I think that when a chat is closed, assuming it's one that had a notification issued, a second message should be automatically added to the notification thread indicating that it has been closed. Otherwise, it will continually sucker-punch users who use the message list as their guide into clicking on the link.
Messages are the sole opinion of the author.
I wish I could shut up, but I can't, and I won't. - Desmond Tutu