User blog comment:Kirkburn/Technical Update: September 2, 2014/@comment-126761-20140902202047/@comment-126761-20140902214222

Just to echo the comment made here:

We have been testing this, of course - unfortunately, the difference between testing and a live scenario for chat can be pretty huge. It's no simple matter to simulate hundreds of varied users across hundreds of wikias at once.

We definitely want chat back working all the time for everyone! It's a much-loved feature :)