In a video posted on Apple Music, Apple announces a “special event” that will take place on June 7 at 9 p.m., two hours after the start of the WWDC keynote.
This event, which is not currently on the WWDC schedule, is related to Spatial Audio for Apple Music, which Apple says will launch later this month. Apple announced that Spatial Audio, powered by Dolby Atmos, will be available to all Apple Music subscribers in June, in addition to higher-quality lossless streaming.

Apple Music Spatial Audio: Own event has so far remained unmentioned
The company has promoted the new features on social media and within the Apple Music app, but there has been no mention of a special event dedicated to the topic. Apple's official WWDC 2021 keynote begins on June 7 at 7 p.m., with the State of the Union taking place four hours later. (Image: Apple)