[Edited to include new Discord server!]
We've set up a Discord server for the game jam which can be joined here (this link is limited to 50 users, so let me know if it gives you any problems): https://discord.gg/rs8cmHH
If you'd like to, you can also join the Game Workers Unite UK Discord as a supporter. In there, we have a #union-game-jam channel which we've been using to plan this game jam, and lots and lots of people who work in the games industry.
You can join as a supporter here (it's free and there's no spam): https://www.gwu-uk.org/support-us
Hope that helps!