The third betas of the future visionOS 2.6, tvOS 18.6, and watchOS 11.6 updates were made available to developers today for testing. Two weeks after Apple released the second betas, the program was released.
The betas may currently be downloaded from each device's Settings app and are accessible to registered developers.
Although no features were identified in the first two beta rounds, we'll update this post if anything new is uncovered. As of right now, there's no news on what's included in the beta updates.