Konami has shared some more details on the upcoming downloadable content for Metal Gear Online. First of all, there will be three new maps, one of which was revealed earlier.
There will also be custom animation called Appeal Actions, and Quiet will become a playable Unique Character, adding to Ocelot and Snake.
The new DLC will be released in March 2016. More information will be provided next week.
Source: Metal Gear Online Twitter (1,2,3)