Please remember that this is a rumor. I have no idea to the validity of this, but there are some details in the rumor suggesting something was seen.
via an anonymous source on Faeit 212
I have a little information for you on a new 40k Faction. Ive seen artwork of two soldiers in heavy but clunky grey body armour and helm, with one wielding an odd looking plasma pistol of sorts. The most striking thing about the image, with smoke and laser fire in the background, is the draping of the red cloth beneath the shoulder plating, and a symbol of the Adeptus Mechanicus on the main figures chest. All I will add right now is the book is 85pgs with datasheets and formations.