But yeah, I agree. 3500/mo is ~4000 usd/mo or ~48k USD/yr. Lots of traveling freelancers probably won't be able to show a minimum of that sustained for 6 months. I'd bet the bar was set intentionally high though, because they're bound to spend a good bit of that directly into the local economy.
I wonder what countries will follow. I imagine there's got to be plenty of poorer/smaller countries thinking about it... A few people making $4k/mo adds little to a country like India or China but in a tiny country that could easily become a decent sized cash transfusion to the local economy.