In a live stream just minutes ago, Firaxis has announced that a new expansion will be coming to Civilization VI next year. Titled Gathering Storm, the biggest addition to the game will be the inclusion of natural disasters. Firaxis is also talking about tweaks done to obtaining energy sources in the game along with the inclusion of different energy types.
The "World Congress" system from Civilization V will also be making a return. They will appear every 30 turns (at normal game speed) and give you a chance to vote on critical issues in your game. Those choices will then influence things about the ecosystem of your map and could have devastating effects for everyone playing. It will also play into the new "Diplomatic Victory" condition.
Civilization VI: Gathering Storm will launch for PC on February 14, 2019. No price has been mentioned yet.