I dont buy this being a Nazi plan; even the article makes it plain that Christaller was a Social Democrat (who are just as against Israel as anyone else in Europe these days, BTW). A party whose members liked to sing Heute Deutschland, Morgen Die Welt would not have included the (to them) purported homeland of die Juden having the Jews alive and dwelling in it.
The actual words to the refrain of "Es Zittern die Morschen Knochen" were, heute hört uns Deutschland, und morgen die ganze Welt (today Germany hears us, and tomorrow the whole world shall). Apparently, anti-Nazi propagandists replaced hört (hears) with gehört (belongs).
Interestingly, after the war, the song's writer, Hans Baumann, became a critically-acclaimed author of children's books, many of which were translated into English and became bestsellers in the US.
You can listen to the song on Youtube:
Es Zittern die Morschen Knochen (The Rotten Bones are Rattling)--Friedrich Ahlers (c. 1936)