The article is rather cryptic. The only known Northrop product that facilitates 5th to 4th communication is the Freedom 550.
This product is publicly known for years except traction for it has remained non committal by the USAF. I don't understand the secrecy surrounding any standing up of such a gateway. In recent years, other solutions had been tested regarding 5th to 4th communications using BACN multi gateway and the U-2/Einstein (EMC2) box if stealth is a must.