If you see top ten active local boards then only Pakistan is the one that doesn't have any separate board, rest all 9 have separate boards. There are few boards that are not very active but still they have a separate dedicated board here.
If you see posting history of Pakistan then its very much evident that they are active for quite sometime now. Don't know whether there are any pre-req for separate board but if there are any, I am sure Pakistani community must have fulfilled them by now.