My personal assumption is that most of Unturned II’s towns and cities would at least be around the size of Unturned 3’s larger cities (ie: Seattle, Moscow, St. Petersburg, Berlin, etc.). Then the “main cities” would probably be twice as large. Maybe.
I don’t think we’ll be seeing cities as large as Cherno is overall, though I’d appreciate having more openness to Unturned II’s cities. They’re all just so compact in Unturned 3.