As MBMM stated, we've been using Discord. The unofficial AG discord and the official ObscureGamers discord servers are where we all went to.
Let's hope not. The TaigaChat framework appears to have been abandoned by the developer, was very outdated and bugs weren't patched. It was quite possibly exploitable. We never reinstalled it and, hopefully, no admin will. By the way, they call it a chat/shoutbox
As Borman said there's nothing we can really do, mods can't really 'run' the site. Also we can't even say when things will change either.
Why not have a link in the navbar to an IRC chat? A few forums I frequent do that. I know it's not the same but, close enough! You can also embed it on the site, too