Apple TV will eventually receive support for displaying content with exactly 24 images per second. The support for 23,976 fps was already present. This addition is not unimportant, because the display of content with exactly 24 fps is not smooth.
Various users are reporting that beta 2 version of tvOS 14.5 has been released. This developer test version adds support for 24,000fps, among other things. Until now there was only support for fractional rates. In movie content, that means the still widely used 24000/1001, or the 23.976 fps format. However, there is gradually more content in exactly 24 fps, especially now that films and series are being recorded much more digitally. Examples of 24,000fps content include the Netflix movie The Irishman and the TV series The Witcher.
This addition enables a smoother viewing experience. Playing 23,976fps content at exactly 23,976 frames will cause syncing issues, but that’s different when playing 24,000fps at 23,976fps. In that case, a frame is skipped every 41 seconds. Not all users notice this, but some do see it and sometimes characterize it as a momentary stutter. On the contrary, playing 23.976fps at 24,000fps results in a double frame every 41 seconds.
For smooth playback of content without stuttering, the Apple TV media player has had the automatic Match Content option introduced with tvOS 11.2 for several years now. With that, the device adjusts the video mode to match the native frame rate of the content to be played. With this mode, the device looks at the frame rate of a video and automatically adjusts the HDMI output accordingly. The Nvidia Shield TV has a similar function, but it is still in beta and does not work with all content and apps.