Epic Games has caught some flak for serving up paid exclusives in its recently launched Epic Games store, such as Borderlands 3—publisher 2K Games agreed to give the Epic Games store dibs for the first six months, a decision that developer Gearbox Software had no part of. Valve has the power to stop that sort of thing though, if it agrees

Source: Hot Hardware – Epic Games Issues Challenge To Valve Over Steam Revenue Sharing Policies And Exclusivity