If you mean Wings icons: those get added when countries host an International Convention. Many people do not like flags much, though, and prefer a different national symbol (such as Kiwis for NZ and the Dala horse for Sweden). Plus, it's impossible to add all the flags in the world. There's just too many. It seems unlikely that all the flags of European countries will be added soon. But if France ever hosts the yearly Anniversary Convention and the French members overwhelmingly want the French flag as a Wings icon, they will probably get it.