Since his uncle Fürst Franz Joseph von Auersperg-Trautson (the husband of Archduchess Constanza of Austria) doesn't have any son but only daughters, Prince Johannes will eventually succeed as Fürst.
One of the reasons I was hoping for a marriage like this. The furst of the Trautson branch of the Auerspergs have continued to marry into the aristocracy/royalty.
Prine Johannes mother is a Countess of Hoyos. His Grandmother was a Countess d'Aspremont-Lynden great grandmother a Princess Of Lobkowicz and so on.