My initial thought based on the video on the website (https://www.ataribox.com) would be an emulation box along the lines of the NES mini built to look like a 2600..

The only thing that makes me thing different, is the various owners of Atari over the years have already put out a load of 'Flashback' devices (I have two myself) and they haven't exactly set the world on fire - so maybe it's ACTUALLY a new console?