https://www.gamespot.com/articles/just-cause-4-leaks-again-prior-to-e3-2018/1100-6459492/

Just Cause 4 has now leaked twice ahead of E3 2018. An ad recently served through Steam (via Kotaku) shows promotional art with a call to pre-order. This is the second retailer listing hinting at the existence of the game, after Walmart spilled the beans on several games with placeholder pages for several unannounced games last month.

Clicking to pre-order reportedly bounced users back to the main Steam page, and the ad has seemingly been removed. We expect to see it announced at the showcase for Square Enix, the current publisher of the Just Cause series. That presentation will take place on Monday, June 11 at 10 AM PT / 1 PM ET / 6 PM BST (3 AM AET on June 12).