Joe Rossignol, writing for MacRumors:

Apple has updated the terms of its AppleCare+ Protection Plan for iPhone, iPad, iPod and Apple Watch to cover batteries that retain less than 80% of their original capacity within the extended warranty period, whereas it previously covered batteries that retained less than 50% of their original capacity. The change applies to AppleCare+ purchased for iPhone, iPad, iPod and all Apple Watch models on April 10, 2015 or later.

Good change.