There is a game feature called 'extra cities' that can be enabled prior to the start of the game. When you have this feature enabled, you will be able to acquire the countries you listed as well as a few others. This option also gives countries more cities and more reinforcements, but it also raises the cost to acquire the country. You need to be premium to enable the extra cities option, so it is an incentive to purchase premium. It might seem silly, but popular maps like 3v3s and CWs will require hosts to make a team game with extra cities in EU+, so they have to be premium in order to host a proper 3v3 and/or CW. Kind of like how you need to be premium to start a WWII.