Maps are not objective, instead they reflect subjective and political realities of the society the mapmaker lives in.
This particular factoid is important when talking about "split states" as well as occupied territories. has been (illegally) occupied by Morocco since 1975 - realiter this will not change any more, yet the maps we used in Geography still identified Western Sahara as its own country, though with a note about its peculiar status appended.
Maps of Germany follow the same trend. Depending on political realities of the day they will either show the GDR and the FRG as unitary or distinct. Usage also plays into this. There were dedicated holiday guides to Eastern Germany, for "Westerners" as an example. Common maps for road travel ("Atlas") had no business showing Eastern Germany, as it was inaccessible. And so on and so forth.
The map says something about its maker, too. In the early 50s you could still find maps of the in its pre-45 borders. With the regularization of relationships between the GDR and the FRG these fell out of use - and became finally obsolescent with the acceptance of the Oder-Neiße-Border in '75.
So in all: It depends on the time and place the map was made. Generally some indication was used that the two Germanies were under different control. This also followed into language. My history teacher told us she still had to use scare quotes around "GDR" in her thesis - to avoid any suspicion of legitimizing the communist regime.