Affected Mac Pro systems suffering from video card related issues are eligible for repair, which consists of swapping out the graphics card.
In the notice, Apple notes that Mac Pros manufactured between February 8, 2015 and April 11, 2015 are eligible for repairs due to issues with the machine’s graphics cards that “may cause distorted video, no video, system instability, freezing, restarts, shut downs, or may prevent system start up.”
Apple goes into a bit more detail about the symptoms eligible for repair:
Distorted or scrambled video on the external display No video on the external display even though the computer is on Computer freezes or restarts unexpectedly Computer will not start up