The repair program is related to the Mac Pro that was manufactured between the 8th February 2015 and the 11th of April 2015, any devices in this period are eligible for repairs.
The problem with the graphics cards on these devices may included distorted or scrambled, if you have one of the issues listed below then you can get your device repaired.
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
Apple will replace the video card on any of the devices affected, you will need to contact an Apple Store or Apple online to arrange a repair.
Source 9 to 5 Mac