From TML Studio talks, i felt that you will not do new maps etc after Denmark, Czechia and Poland (To cover all Germany-neighbours), but i hope that's not true feeling
I doubt that's true. I think that adding all of Germany's neighbouring countries is just a priority before implementing any further countries, which is just a logical order of expansions. For example, you can't really drive to the Baltic states without driving through Poland Besides that, new map DLCs are a win-win situation for both the developers and players.