User blog comment:Kogath/Monster Hunter: World Discussion/@comment-25083735-20190604201317/@comment-24734669-20190604203352

The Leviathan skeleton got murdered by the new engine, though. In fact, just about anything with an overly long neck that fights like a normal boss did.

There's also no place for Astalos and Mizutsune to fit as well. Nargacuga is in the Ancient Forest, so Astalos can't really be there; as well as this, there's not enough water in the Coral Highlands for Mizutsune to be near, and there's an overwhelming chance that Zinogre will be the rival apex of the Coral Highlands.