Follow the headline link to the release notes, then search for “New Features”. Rinse and repeat. So much to see.
One particular nugget I can’t wait to take for a spin:
Audio sharing is compatible with AirPods (1st generation or later) and PowerBeats Pro. iPhone 8 or later, iPad Pro 12.9-inch (2nd generation or later), iPad Pro 11-inch, iPad Pro 10.5-inch, iPad (5th generation or later), iPad Air (3rd generation), iPad mini (5th generation), or iPod touch (7th generation or later) is required. (51331268)
One definite benefit to keeping those first gen AirPods around if you upgrade to gen2 or the PowerBeats Pro.