Everything Gleam happens in the Discord channel. Gleam's use of Discord is so successful, it's a strong community in the sense that if you nuked all the git repos the Discord would probably rebuild the language, whereas if you nuked the Discord channel the language would probably die.
That said, there are downsides to Discord as a platform. Critically, you need an account to log in and view it. I am relatively young and relatively terminally online, but people who are not are less likely to go on Discord imo. And Discord is a company, who knows what it will do, notably it just launched teen-by-default settings, so its verification requirements could block some users.
Also, the Discord is incredible in that you can ask a question and someone like Louis (Gleam) or Hayleigh (Lustre) will respond. This is works great now, but if Gleam got huge would probably be too much of a burden on their time and entail a lot of duplicate or low quality questions. Still, for now it works, so enjoy it while you can, it's like having Anders Hejlsberg on speed dial for your dumb timestamp parsing questions.
One solution might be to export the Questions channel to a public wiki. I think currently Louis/Hayleigh prefer people ask questions rather than read a wiki, so they can give them XY answers ("why are you trying to do X in the first place? what you really want is Y").
I also like Zulip, specifically FHIR's Zulip instance chat.fhir.org which is similar in that you can ask very knowledgeable people questions, but unlike Discord can also be viewed without logging in. I have not really looked into Zulip though and there would probably be a lot of friction in moving, as many people are more used to Discord.
And again Discord has worked so incredibly well for Gleam that it probably will stay the main place for everything, even if Discord adds a bunch of verification requirements. Maybe the real Gleam was the friends we made along the way.