Here's the admittedly tenuous situation: A Reddit user under the handle "OurRobOrRos" recently posted the image you see above. He or she claims that it was part of a screencap taken from the German version of Origin a short time ago. As you can see, the image indicates a February 18 release date for the PC version of Second Assault, a DLC pack that will bring four fan-favorite Battlefield 3 maps to Battlefield 4.
If this release date is accurate, it becomes simple to extrapolate the Second Assault release schedule based on EA's previously-announced DLC plans. Second Assault is slated to reach Battlefield 4 Premium members across all platforms first, about two weeks prior to the general public receiving the downloadable addition. Thus, Second Assault would reach Battlefield 4 Premium users on PC, PlayStation 3, PlayStation 4 and Xbox 360 on February 18, then become available to the remainder of players in early March. Xbox One users received Second Assault as a timed-exclusive with the launch of their iteration of EA's shooter.
We contacted EA for a comment on this discovery, but were told that the company is currently unwilling to assign a release date to Second Assault.