EA announced that PS4 owners who do not have Playstation Plus will still be able to experience the online beta for Battlefield 1. The statement was made via Twitter...
@SpartanB013 You do not need a PS Plus account to play the Battlefield 1 Open Beta on PlayStation 4.
— Battlefield (@Battlefield) August 26, 2016
Great news for anyone who doesn't have the service but has an internet connection! The beta will begin August 31st across all platforms.