funny you should ask ....
There isn't an official TMD discord server (at the moment), and I don't know of any other vintage-specific Discord server (though feel free to post one here if you find it)
There is a semi-official IRC channel,
EFNet. That IRC channel existed LONG before I ran the site, and I used to spend a TON of time there, but I don't know how active it is today. (I know it's not dead, but probably not that active.)
However ... I had been considering making a private TMD Discord as a bonus for TMD Patreon supporters - and possibly for Subscribers on my/other vintage streamer channels. I made the server, it exists, but I haven't figured anything out around permissions/invitations/tiers etc.
I'm absolutely open to the idea of a public and/or private TMD Discord, but I haven't gauged the interest level yet. If that's something people think they'd use, definitely let me know.