At the current time, third-party music services like Spotify can only be streamed on the HomePod using AirPlay and an iPhone, iPad, or Mac. The new feature will presumably allow Spotify and other music services to be set as the default music service, letting users ask Siri to stream music by specifying “with Spotify” at the end of a request.
Apple didn’t mention the tidbit while introducing its new software updates, but the feature was highlighted when Apple was introducing new HomeKit features.
In a HomeKit slide covering the new Home app, there’s an icon of the HomePod along that reads “third-party music services.” Support for third-party music services was rumored ahead of the release of iOS 14, with Bloomberg suggesting Apple would implement the feature.
The new HomePod software is not available yet, so third-party music service support won’t be able to be tested at this time. The HomePod is also getting a new option that will allow Siri to announce when a HomeKit-compatible doorbell is rung.