What Happened to the Whole Concept?

I mean, I may be wrong (it's been 7 years now), but at the beginning FFXV was supposed to be a part of the Fabula Nova Crystallis mythology, clearly named "FINAL FANTASY XIII"... And I can remember Nomura saying something like "If FFXIII is the light, then Versus is it's shadow". I guess fal'Cies and l'Cies have disappeared from FFXV by now...