Mine is 13'' 2015 model, bought it in 2016, warranty is out but they accepted it on replacement, waiting on service centre to return it.
One month ago i noticed one small dot in left bottom, planed to visit service but really needed my computer and in meantime in one month time it started on other parts of screen.
Most annoying part of this problem is that Its mostly used at desk, maybe i have to close it couple of times in month when i have to meet clients. And cleaning was always with that cloth that came with it, sometimes just plain water.
So now most of my worries are will that replacement screen have same problem in future, and how to prevent this.