The issue was originally related to iPhone's being throttled at a certain battery health without the user being notified. It does not seem that they throttle iPads in the same way when the battery degrades or at least no one has proved it like on the iPhone side. If you are trying to find the battery health on an iPad, I recommend using software like 3U Tools (PC) or Coconut Battery (Mac) to read the data. They work across all iOS devices and give you pretty accurate data regarding batter health. We use these just to confirm that what the device says in iOS actually matches what the software is pulling.