The muse just speaks of a claimant, not an heir. Its entirely possible there is something else going on here. While he never took on the title of king, baron wulfenbach ruled over the majority of europa with an iron fist for decades, AND he had a son and heir to take the "throne" who officially did so. Gil is the defacto ruler of europa despite there being a civil war going on. Think of it this way, if queen elizabeth and her entire known line stopped being queen of england, and 15 generations later someone else took over and ruled then put their child on the throne to replace them, which family line is the TRUE royal line? What happens if one of elizabeths many times great grand nephews shows up and declares he is rightfully the king? Who has the legit claim to the throne? The current king? Or the distant relative of the royal line that hasnt ruled in centuries?