User blog comment:Kogath/Monster Hunter X Discussion/@comment-27089351-20151018000158/@comment-26450094-20151018092222

You should at be happy that they at least give us 6 big monsters. Remember that this is a Freedom game, and Freedom don't usually add too many monsters. MHF only had Garuga, MHF2 Tigrex and Akantor, MHFU Nargacuga, King Shakalaka, Queen Vespoid and Ukanlos; and finally MHP3rd Zinogre, Duramboros, G. Wroggi, Nibelsnarf and Amatsu.

It's true that MHP3rd also added subspecies, but we can't know if they have added any new sub/variation for now, we don't even know if there will be subspecies.

But well, I suppose they at least have other one new monster, the online boss. Not sure about offline, remember Rusted...