We’ve reported this before. The reason for a failed backlight is the connection cable to the display, which is very thin and a bit too short. This puts excessive mechanical stress on it and causes it to fail accordingly. Current series already seem to have a longer cable, Apple is repairing faulty models now.
Apple’s repair program refers only to 2016 MacBook Pros, either with Touch Bar or with function keys. Other series should not be affected by the bug. If you have a model that has this bug, go to Apple’s support page and register your device for a free repair.