Capcom says that there will be a closed beta period for Street Fighter 6 coming this October. Specifically, the closed beta will run from October 7-10. The test seems to be mainly focused on the game's crossplay support, meaning that the test is going to be for the PlayStation 5, Xbox Series X|S, and PC versions of the game.
Those of you who are interested can sign up for the beta. The page also offers a look at additional details...