In this particular case, one of my favourite RPG writers posted about it on MeWe. He, together with some other RPG writers, runs the place. It's tied to their Patreon, they organise talks and workshops for members. Most of the channels are about RPGs of course, but they have channels about tons of other topics too. One of my favourites is their channel about TV & movies, because there I get to discuss TV shows and movies with people who tend to have a similar taste as I do.

It's absolutely an echo chamber; it's mostly people who grew up with British roleplaying games in the 1980s and still love them today. But it's a fun group.