I've been recommended /r/pl a lot but it's not quite the same vibe as LtU. I think LtU was very carefully curated professional research with commentary, while /r/pl has a lot more amateurs asking questions about their hobby languages — which is great, I'm happy that people are experimenting with programming languages, but it does make it hard to use as a way to keep up with the latest big results for someone who doesn't necessarily have the time to follow everything that's going on on the subreddit.

Maybe the Discord is the way to go. The user interface confuses the heck out of me, though. Appreciate the recommendation!