In 2021 I would like to see Germany re-build finished. SCS did a very nice job there and raised the quality standard in the base map which is respectful.
After Iberia, It will be great to see Western Balkans, but I think that Balkans will wait a little bit more. Based on screenshots we have seen it's 90% sure that's a further east (Ukraine, Belarus, Moldova and more of Russia).
In very first release stream for Baltic Sea, there has been a question for Pavel, is there any plans on going further more into Russia and he said that is possible in the future, not just for Baltic Sea DLC but for any else. Which has been true since we got expansion for France and Italy on Corsica and Sardinia.
So based on that it might be that those screenshots are not next "main" map expansion, it might be expanding Baltic Sea, more beyond the Baltic Sea.
Just remember teasing screenshots from Carthoo for Corsica and Sardinia...