The HomePod User Guide »

Got a HomePod on its way? You can get a head start on checking out the User Guide starting now. Don’t miss all the ways you can control the device, what types of things Siri can handle and what a user can do with your personal data if you enable the feature.

Awkwardly, at least at the time I published this, this page refers to AirPlay 2 more than once, but doesn’t seem to list any features that are being held back until AirPlay 2 ships later this year.