Why was the Supernatural series removed on Netflix Germany?
Because the license has expired
A streaming service always pays a license that is only valid for a certain time. There are several options. There's also a 7 day license that TV stations use, for example, to be able to stream the series after watching television in their media library.
If, for example, Netflix now pays 20,000 (Supernatural is definitely more expensive) and the license only lasts for 2 years, then Netflix has to pay another 20,000 or take the series and the movie down again.
Because Netflix can't extend all productions because it always costs money, series and films are also removed.
Incidentally, this does not mean that they will never buy it again. Series and films came again.
