Apple issued the iOS 12.2 beta 1 update this afternoon, and developer Guilherme Rambo soon discovered a hidden setup screen that uses "Hey Siri" to activate Siri on AirPods via iPhone, which is not supported by the current AirPods, meaning that the second generation of AirPods is coming soon.
Users will be asked to set up the "Hey Siri" feature when pairing the AirPods to an iOS device for the first time. The biggest difference between using Hey Siri on the new AirPods is that AirPods itself recognizes and sends commands to the paired device, this means you don't have to take out your AirPods, as long as the iPhone is in your pocket and you can summon Siri.
It's been rumored for a long time that Apple to support "Hey Siri" for AirPods, Apple itself leaked some clues during the WWDC 2018 Keynote's presentation video, where you can see the heroine used AirPods to ask Siri how to get to Apple Park as fast as possible.
Since the update includes this new setup screen, it is highly possible that Apple will soon debut the new AirPods, perhaps following the release of iOS 12.2.