They didn’t say much about it, this is all of the official word that accompanied this image:
HARBINGER WARS #3 (OF) 4.
JOSHUA DYSART. DUANE SWIERCZYNSKI. CLAYTON HENRY.
The image, of course, is an homage to the original cover to Harbinger #10, the first appearance of the H.A.R.D. Corps back in classic Valiant.