Against all odds, Samsung has now officially announced the release of the One UI 4.0 beta. The beta will arrive on Galaxy S21 series units shortly, with owners in China, Germany, Poland, the US, the UK, and India immediately eligible to sign up.
https://www.notebookcheck.net/Samsung-releases-the-One-UI-4-0-beta-arriving-on-Galaxy-S21-units-around-the-world-imminently.561191.0.html