Having a damaged iPhone 6 Plus that requires a whole-device replacement entitles owners to a replacement with iPhone 6S Plus, as stated in a redistributable memo across Apple Authorized Service Providers today.
According to the iPhone manufacturer, “orders for whole unit service inventory of some iPhone 6 Plus models may be substituted to an iPhone 6s Plus until the end of March 2018.” This is no mere hearsay, however, as MacRumors has validated the legitimacy of the claim across multiple sources.
See also: How to check if Apple is slowing down your iPhone because of the battery
While the company did not specify which specific models qualify for the replacement nor what was the reason for offering iPhone 6S Plus instead, one probable reason for this move is to substitute the device which was troubled with replacement battery shortage.
Coming from a separate memo which was acquired by MacRumors, it was stated that Apple is no longer manufacturing the iPhone 6 Plus which suggests that an “apple-to-apple” replacement for the same device would be difficult. Although a reboot of the iPhone 6 Plus’ production may seem like a logical solution from Apple to cover for its faulty smartphone, replenishing the supply of both the batteries and the units themselves would require significant time to attain.
Many hardware issues often require a whole-device replacement. But if your device only suffers from a faulty display, camera, battery, speakers, or the Taptic Engine, these problems are usually fixed by Apple and its authorized dealers by replacing the actual part individually.