MacRumors published a story that Apple has released the iOS and iPadOS 14.6 release candidate to registered developers.

Apple Seeds iOS and iPadOS 14.6 Release Candidate to Developers

Apple today seeded release candidate versions of iOS and iPadOS 14.6 to developers for testing purposes, with the new software coming one week after Apple seeded the third iOS and iPadOS 14.6 updates. iOS and iPadOS 14.6 can be downloaded through the Apple Developer Center or over the air after the proper profile has been installed on an iPhone or iPad. iOS and iPadOS 14.6 add support for Apple Music features, including Spatial Audio with Dolby Atmos and Lossless Audio. 

Apple Seeds iOS and iPadOS 14.6 Release Candidate to Developers