Here's the good news first – if you're an Apple TV 4K owner, you can finally watch YouTube videos in glorious UHD 4K resolution? The bad news? You'll still get a better experience using other devices.
So long as your 4K Apple TV device is running tvOS 14 or newer, you should start to see support for 4K videos in Google's streaming video player soon.
However, you'll still only get 30fps frame rates, and there's no HDR support for the app on the Apple TV 4K device. You can get to 60 frames per second, but only at 1440p resolutions.
Streams behind the competition
YouTube has also confirmed that a 4K / 60fps mode with HDR should be coming to iPad and iPhone soon, but it's not tied to an app release, but instead a remote update, meaning it's unclear when it'll be universally available.
While the Apple TV update widens the pool of 4K content someone can watch without dipping into their pockets to Apple's movie purchasing options or a paid-for streaming service, it's still leagues behind even some of the most affordable, best streaming devices and sticks. The premium paid for Apple's gadget right now still doesn't feel worth it.
At least though it shows Apple widening file format support on the device – its avoidance of the VP9 codec was what had previously kept Apple TV tied to 1080p streams, Google's codec of choice.