Will the new Apple TV actually output 24p video at 24p so that TVs/projectors so as to avoid pulldown?
No, the device output framerate is fixed, and content is automatically converted during playback to match the selected device output framerate. Apps do not have the ability to affect the device output framerate.
If you have a scenario where you believe that this would be required, please file a bug at bugreporter.apple.com with details as to why this would be required for your application.
sigh. That YouTube video is worthless and offers nothing relevant to the argument made here. He's merely saying that 24 fps by itself won't recreate the "look" of film. But, the fact remains that most film is still shot at 24fps and provided at that frame rate in today's media (be it DVD, Blu-ray, or digital). And when you watch 24 fps content on an inferior product like the Apple TV, which is limited to 60 Hz output, it must artificially add frames in a non-consistent way that leads to judder and temporal artifacts. Sure, it'd be great if film were shot at a higher framerates, but I have no way of controlling the original framerate. Apple on the other hand has every opportunity to output the video in its native framerate. That's a feature that's been standard on most DVD players for a decade. For a company that prides itself on the purity of music, this is a laughable omission on their part. As an electrical engineer that's designed many ICs used in audio/video devices, I can confidently say this would be a trivial feature to offer (I'd be mildly shocked if the video chipset they're using doesn't already support that). And while I own virtually one or two of every Apple product (yes I'm an Apple fanboy), I sadly cannot include an Apple TV in that list until Apple takes video as seriously as it does audio. I'm perfectly content using my Nvidia Shield TV in the meantime.