Apple、デベロッパー向けにmacOS 12.4 beta (21F5048e)、iOS 15.5 beta (19F5047e)、iPadOS 15.5 beta (19F5047e)、watchOS 8.6 beta (19T5547f)、tvOS 15.5 beta (19L5547e)を配布開始
https://developer.apple.com/news/releases/