https://wccftech.com/samsung-publishes-one-ui-4-0-upgrade-rollout-schedule/

Samsung has been consistently and properly pushing One UI 4.0 Beta update based on Android 12 for some time now. The update has rolled out to a few of Samsung's flagship devices, including the Galaxy S21 series, as well as the Galaxy S20 and Note 20 series. The beta is also available on the Galaxy Z Fold 3 and Galaxy Z Flip 3 series, and now Samsung has pushed a new notice on the Samsung Members app that suggests that the stable builds of Android 12 are not that far.

Samsung seems to have "accidentally" pushed a notice on the Samsung Members app, revealing the One UI 4.0 stable rollout schedule for its devices. As per the notice, One UI 4.0 based on Android 12 will start rolling out to the Galaxy S21 series this month, and that will be followed by the Galaxy Z Fold 3, Galaxy Z Flip 3, and Galaxy Note 20 series, and so on. You can check out the image below shared by FrontTron.