The next Apple TV model could support refresh rates of 120Hz, presumably at 4K, according to a report from 9to5Mac. References to “120Hz” and “supports120Hz” appear in the latest beta version of tvOS 14.5, suggesting that Apple is, at a minimum, testing this mode.
Higher refresh rates would allow for smoother media playback and, more importantly, improve Apple TV for gaming. The current 4K Apple TV only supports 4K up to 60Hz, the maximum allowed by its HDMI 2.0 port. If the next model supported 4K 120Hz, it would have to use the HDMI 2.1 standard which allows data rates to be doubled. It would also require a compatible 4K 120Hz TV, but there are many now available from Samsung, LG, Vizio, and other brands.
Rumors have surfaced lately that the next-gen Apple TV will have a high-end A14X processor with console-level performance. Also, Apple has reportedly invested more money in its Arcade service lately and recently expanded its catalog by 30 games. With all of that in mind, it would make sense to use 4K 120Hz refresh rates to future-proof the box and provide a better gaming experience. The next Apple TV is reportedly on track to be released in 2021, according to a Bloomberg report from the end of last year.