A high-end version of AirPods with noise cancellation, water resistance and extended wireless range.
Each iOS update usually goes through several beta reviews before a wide public release. It is possible that this mention of AirPods and "Hey Siri" will disappear. A future release, similar to the way Apple removed AirPlay 2 and Group FaceTime from previous versions.
Apple recently launched new Smart Battery Cases for iPhone XS, XS Max and XR. The company is also rumored to be, yes, still, finally approaching the availability of its AirPower wireless charging platform for iPhones, Apple Watch and AirPods. Apple originally showed off an updated AirPods case with wireless charging capabilities when it first announced AirPower.
If AirPower is also nearly ready, that case could be part of the revamped AirPods hardware when Apple finally brings them to market.
Certainly, they are due to this point: several of my friends who were early buyers of the original AirPods say the battery life isn't what it used to be. But two years later, many are still buying them in droves.