AppleCare Protection Plan are additional warranty coverage that you pay extra to get 2 more year coverage from the standard 1 year. You must register your Mac before the first year expired.

For the coating issue you can try contact Apple if they still offer free replacement. They used to offer it for unit affected and within 4 years of purchase. This has nothing to do with warranty. Apple do it as quality recall.

This post has been edited by wei: Apr 10 2020, 09:19 PM