That was back in 2015 and the offer would allow users to claim it within 3 years of their laptop’s purchase, which means that come 2018 that program will come to an end. However the good news is that it looks like Apple will be extending that program. According to MacRumors, they have obtained an internal document distributed to Apple Authorized Service Providers which states that this program has been extended from three years to four years.
This means that instead of ended in 2018, it will now end in 2019 or even 2020, or at least for certain devices. This covers the 2015-2017 12-inch Retina MacBooks, as well as 2013-2015 MacBook Pros. It also appears to cover 2016-2017 MacBook Pros, although it seems that this is a problem more associated with the 2013-2015 models, but we suppose better safe than sorry.
MacRumors is also claiming that the internal document states that Authorized Service Providers can replace a damaged display free of charge, as long as the anti-reflective coating issues are present. This means that even if you sent it in for another display-related problem, it could be replaced for free if the coating issues are present.