It what can be seen as a victory for players, Sony has apparently cancelled the requirement for players to link their Steam account with the PlayStation Network if they want to play Helldivers 2. This was revealed through the official X account for PlayStation.
In a post on the account, Sony said they've heard the feedback and revealed that the account linking requirements "will not be moving forward." The post went on to say that they're still looking into what works best for PC players and to provide an update on future plans.
