Well, the unimaginable happened, or Apple changed their policies, because they just replaced my son's 88% capacity iPhone 7+ battery for free under AppleCare+ tonight, with about 3 months remaining on his AC+ warranty.
You got it for free cuz you had AppleCare+. If this were under "normal" circumstances, before all this scandal with the throttling, Apple wouldn't replace the battery even if you had AppleCare+ unless there was something wrong with the battery (below 80%).
Due to the scandal, you can now replace a battery for just $29 for whatever the reason. Added to that, anyone with AppleCare+ will have the $29 fee waived.
If you did this next year after the cutoff period, I guarantee they wouldn't replace your battery.