On December 10th (UTC), Ryozo Tsujimoto, the main producer of Monster Hunter: World, has introduced the future updates for the game in the live broadcast of the Special Developer Update. (The updates below are based on the console version of Monster Hunter: World.)
The biggest update was the announcement of the next expansion, Iceborne. The Iceborne expansion will have new locales, monsters, quest ranks, and equipment. The Iceborne expansion will be released in fall 2019. You will need the original Monster Hunter: World to play the expansion, and Ryozo mentioned that the expansion will be the size of previous “G” or “Ultimate” entries in the series.
Also, Arch-tempered Kulve Taroth and Nergigante will be added. The regular Kulve Taroth will not appear in the game after Arch-tempered Kulve Taroth, but the rewards you could get from Kulve Taroth will be available from Arch-tempered Kulve Taroth, and in addition, Arch-tempered Kulve Taroth will give rainbow-grade items. If you fulfill certain conditions before it sheds its gold plating, you can push it into a new “furied” state for better rewards. You can obtain new weapons as well as a new gamma series armor made from Arch-tempered Kulve Taroth materials. Arch-tempered Kulve Taroth will be available from December 19th 3:59 P.M. to January 3rd, 2019 (PST).
Along with Arch-tempered Kulve Taroth, you will see an Arch-tempered Nergigante as well. Arch-tempered Nergigante will be added in spring 2019.
Before Arch-tempered Nergigante, a new collaboration is coming to Monster Hunter: World. The new collaboration event after Street Fighter, Mega Man, Horizon Zero Dawn, and Devil May Cry will be The Witcher 3: Wild Hunt.
You can meet Geralt of Rivia as the main character of the first collaboration event of 2019. Details regarding how to get Geralt gear have not been announced yet, but the event is scheduled to begin in early 2019, so details are expected to be revealed in the near future.
Other updates include the Appreciation Fest celebrating the first anniversary of Monster Hunter: World, and a ton of exciting events celebrating the 15th anniversary of the Monster Hunter series. Details on the events are to be revealed soon.