User blog comment:Kogath/Monster Hunter XX Discussion/@comment-31382534-20170228041900/@comment-26421638-20170228172929

Wait wait wait... Let's check the list of the refereces to old Monsters in Gen


 * Fatalis: We tecnically have its gear in Gen, but we don't know if returns or not.
 * Monoblos: Daimyo/Stonefist's skull, we know that Diablos returns, but we have no idea about Monoblos.
 * Gravios: Shogun's Skull, Gravios returns in MHXX.
 * Shen Gaoren: Cottonmouth already explained it, but we know that Lao-Shan returns and we know that there will be another Monster in the Fortress.
 * Lunastra: an HBG that looks like a Lunasta-shaped Statue, we don't know if she returns or not.
 * Great Jaggi: Nothing more than G. Jaggi scraps.

However, all of them (except Gravios, is already confirmed) have a great chance to return. Let's hope for the best.