No. Support for 120Hz refresh varies by title. It’s far less enforced than resolution on the Xbox Series X, and on consoles in general. Even resolution tends to be very variable on consoles as you know, with upscaling, dynamic adjustments, and checkerboarding a lot more common than on PC.
As for refresh rate, the list of games that offer a 120 frames per second mode is currently small but will grow. Keep in mind most titles will lower resolution and effect quality to maintain the higher refresh rate, so it’s up to you to decide if you like the tradeoff. We’ve experimented with games like The Falconeer and Dirt 5, and they now do support 120Hz on the new Xbox console. We can also fully confirm 120Hz multiplayer for Call of Duty Black Op Cold War on Xbox Series X, which not only works but is glorious.
Also, let us know if you have any concerns via support or BenQ online chat (click on the icon at your bottom right corner).