As you've noticed, the chat feature has disappeared...Or has it?
We've modified the chat to be available when Jack, Blackwell, and other Third Man VIPs are online, and then closed when they leave. Over the years we've come to realize that the vast (VAST!) majority of people only use the chat when our fearless leaders are present, while rest of the time we spend a vast (VAST!) amount of time reprimanding problem users, telling people to please not use a swear, mind your manners, if you don't have anything nice to say, don't say anything at all etc. Comments on posts, it should be noted, are still active.
While we certainly want to continue forth with the community that you and we have built over the years, the Chat function being available all the time served a purpose that has waned in popularity, and lead to more problems than two people can deal with in between regular day-to-day Vault duties.
So in closing, rest assured, the chat is still there. When Blackwell/Jack/Swank want to give away ultra-rare items and curios, shed light on any one of the mysteries of Third Man, or just some good old-fashioned coffee talk, a "CHAT" icon will appear in the menu bar on the main page, a tweet will be sent out as before, and the madness shall ensue.