I'm almost 100% certain Atari was outboarding (by the way, we had easy access to an email address at the CES website for reporting that stuff..... Anyone here utilize it?)
I can agree that its possible for Atari to fake the gameplay footage still, but I personally dont feel it's too likely at this point.
Also, dont forget that a fake x86 board running inside the VCS casing is still a functional board nonetheless-- that means it's generating heat and needs a cooling system of some kind that happens to perfectly match with the casing's air vent placement. If anyone here has built a computer before, you'll know how important airflow is to keep things cool. A regular heatsink on a generic x86 board usually points upward, not sideways. Otherwise, Atari probably had demo units shutting down suddenly pretty often. Lol.
As much as i am skeptical about Atari delivering anything to me, let alone delivering a GOOD console, my gut is telling me that their bootup/gameplay footage was more than likely authentic-- as rough and slapped together as it was. Going through the trouble to find another x86 board that happens to fit and function inside that extremely compact VCS case just seems impractical and unlikely to me (unless it was a raspberry pi, but that doesnt run windows or the Atari Vault).
But that all being said, I'm leaving the door wide open for anyone to convince me otherwise and be like "ahh.......... gotcha.... sorry... o w o".