If you replace the battery in the newest iPhones, a message indicating you need to service your battery appears in Settings > Battery, next to Battery Health. The “Service” message is normally an indication that the battery is degraded and needs to be replaced. The message still shows up when you put in a brand new battery, however. Here’s the bigger problem: our lab tests confirmed that even when you swap in a genuine Apple battery, the phone will still display the “Service” message.

Thing that we see here is that battery is also small computer now and requires authentication.

And it is only first step, second will be full blockade of unauthorized battery replacement, watch the news for horror stories of exploding Chinese third party batteries, will be soon in all major channels.

All, 100%, new upcoming Apple notebooks will have same feature where each and ether component, even soldered BGA chips will require authentication and replacement only by authorized service. MY source confirmed that Apple intent to fully, 100% crack down on any third party service for new products, as well as later destroy Hackintosh (by going to proprietary LSI).

https://www.ifixit.com/News/apple-is-locking-batteries-to-iphones-now