I leave a browser tab open on the Server Fault homepage. This afternoon after being away for a short while I saw the notification:
When I clicked it, all I saw were old questions.
On checking a few of them, I found that all of the questions had an old answer that had recently been made community wiki.
When I reloaded the home page, all of them were gone, leading me to believe that old answers made CW shouldn't appear on the home page.
So, I suspect that either these old posts being made CW should be appearing on the cached home page, or we should not be notified of them via the websocket.