As of July 26, 2017, Apple will no longer replace the 15-inch MacBook Pro with battery issues with a newer model, this pertains to models assembled mid-2012 and early 2013.
Prior to July 26, 2017, any customer having battery issues with their 15-inch MacBook Pro with Retina display that failed Apple’s battery diagnostic test would receive a newer 15-inch MacBook Pro with Retina display.
Apple sent an internal memo to its Genius Bar employees and Apple Authorized Service Providers advising its employees to order the necessary inventory for replacement instead of replacing it with a newer 15-inch MacBook Pro. The replacement part would arrive within 15 days of the order date. One of the reasons for this change has to do with Apple no longer assembling the mid-2012 and early 2013 models, and the closest to exchanging a functional equivalent model was a refurbished 2015, 2016 or 2017 model, however, this created a problem because Apple was charging a fee of only $199 for out of warranty battery fee for the entire replacement of the MacBook Pro.