Interesting.
Clearly, Apple knows this is not just a defect limited to the 6s (its not like there has been major battery manufacturing changes between 6, 6s and 7 devices). Some 6, 6 plus and 6s plus users are reporting this exact same issue. I have 2, 6 devices in my home that are dying at about 30%. Have been for about 4 months (give or take, has felt like a year). And they go form fully charged to dead in about 2 hours. Tops.
My guess is Apple is not really looking to announce some major battery recall program, spanning 3 generations of devices, with all the "uh oh" battery buzz in the industry at the moment. Nah. They'll lay low. Address the latest build to experience this issue (the 6s family) - as the 7 devices are still too new to see this battery issue - to convey an image of "making it right." Which is better than not taking any steps to remedy. My prediction: about a year, year and a half from now, 7 users will be experiencing this same issue.
I suspect they will eventually extend this battery replacement program to the 6s plus. But not for a few months (March/April?). Gotta space out the recall announcements. Bury them amongst other product spec bump announcements. I also suspect they will never address this issue with 6 users. By the time they have adequately addressed the 6s plus, the 6 will be nearly 3 years old. And the next gen device will be close to shipping and the pending release will obviously consume all of the headlines. #movingon
I could be wrong.