Civilization 6 update 1.12 was released today on January 28. The full set of patch notes confirm a new DLC and multiple bug fixes.
The biggest addition that is confirmed for this update is Vietnam & Kublai Khan Pack. This is available now, as part of the New Frontier Pass, or as an individual $8.99 purchase. In addition to this, various bug fixes and improvements were made in a free game update that launched today.