Was catching up on forums from overnight, and noticed in one thread that these boxes were missing. Is this the new way of Admin saying "Drama, thread closed"? Maybe there was an announcement somewhere and I missed it.

It's not a new way, it's how it's always worked. Closed threads don't give you the option to respond precisely because they're closed off. I don't always have time to make a new post about why I closed a specific thread, and often times it will be pretty self-evident, so if you are logged in and do not see the reply and quote buttons, assume I have closed it.