During a Reddit AMA with Andrey Doronichev, the director of Google Stadia, he clarified that the service’s subscription is not meant to be the “Netflix for games”. According to him, “To be clear, Stadia Pro is not “Netflix for Games” like some people have mentioned, a closer comparison would be like Xbox Live Gold or Playstation Plus. The Pro subscribers get 4K/HDR streaming, 5.1 sound, exclusive discounts and access to some free games. Roughly one free game per month give or take. Starting with Destiny 2 (yay!).”
It basically sounds like if gamers want to be able to stream in higher quality, that’s what the Pro subscription is for, and any of the additional features are simply bonuses that will be part of the subscription. Gamers will still need to purchase their games if they want to play them, with Google reassuring them that even if the developer/publisher decides to stop supporting Stadia, they will still be able to retain their purchases. Stadia is currently set for a launch this coming November.