Final Fantasy XV: Any references to FF XIII and FF Type-0?

While they may be apart of the Fabula Nova Crystallis sub-series, they are all their own individual games with no reference to one another - except for the XIII trilogy. The reason why they are apart of the sub-series is due to common mythology within the games

Fabula Nova Crystallis Final Fantasy is a series of games within the Final Fantasy video game franchise. It was primarily developed by series creator and developer Square Enix, which also acted as publisher for all titles. While featuring various worlds and different characters, each Fabula Nova Crystallis game is ultimately based on and expands upon a common mythos focusing on important crystals tied to deities. The level of connection to the mythos varies between each title.

........

The universes of XIII, Type-0 and XV are unrelated to each other, though common elements and themes are present