More information will be revealed at PAXWest
You may know about it if you are interested in and watching every leagues of Dota 2. At Dota 2 TI8, Gabe newell announced that a lot of info will be revealed about Artifact at PAXWest. He also said that everyone attending TI8 will receive a copy of Artifact and beta access which will begin in October. And the game keys at PAXWest will also grant beta access. About beta, beta will be released at October, and players can compete through tournaments. You can see his annoucement below, and I can't wait to see more about this game!