Nothing launched the Phone (3) in the event yesterday, and the firm also confirmed a few details about Nothing OS 4.0 and when it might potentially arrive.
Towards the end of the Nothing Phone (3) launch event, the company confirmed that Nothing OS 4.0 will arrive in Q3 2025. The firm did not share the exact release month, but since we're already in Q3, we expect the firm to start pushing out initial Nothing OS 4.0 Beta by the end of July 2025 or at the start of August 2025.

The stable release could happen in September, considering the amount of time the firm usually takes to polish things out. Nothing OS 4.0 will be based on Android 16, but we're vastly unaware of the potential new features it may bring.
The latest Phone (3) should be the first to receive the Nothing OS 4.0 beta and stable updates. It could be followed by the Nothing Phone (3a) series. Based on when the devices were released, the update should then roll out to the CMF Phone 2 Pro, Nothing Phone (2a) series, CMF Phone 1, and finally, the Nothing Phone (2).
Nothing OS 4.0 will be the last update for the Nothing Phone (2) and CMF Phone 1. However, they should continue receiving security patches for a few more years. The company is yet to confirm a release timeline for all the eligible devices, but we should see more information pop up as we get closer to the release date, which is also unknown.