Without some controls or a lot of moderation, this is going to rapidly devolve.
And what is the value proposition compared to Reddit or some other existing, nomad-specific sites?
What if there isn't a "value proposition"? Some times the value comes from people using it, and people find their own value in it organically. With forums, if people use it, it has value.
The nomadlist slack is effectively a forum in this niche that's a lot more active, and people tend to follow the rules because you have to pay $100-$300 to get in. Not really sure it's worth the money though. I do like the idea of accounts having a cost so the service can pay for mods & hosting, but the price is a bit steep. Something in the price range of something awful forums might be better, because there's a lot of real nomads who wouldn't pay $100 just to get in a slack.
Well this particular forum is owned by OP. That's the value proposition for him. Now, for users, I'm not sure there is a value proposition to be a part of a dead forum.