Some of the terms in this game began as acronyms.
ORN could easily have been Operative Robot Network, but Khaos is a bit harder. Maybe it used to be CHaOS, for Controlling Hegemon and Operating System. The Thunder Force 3 spelling (CHA OS) supports this.Reason I say this is because ORN began as a network of robots, and for all we know remains one as of the games.
ORN Faust in 'VI' is a merger of Khaos and Cenes Crawford.
In the Syrinx transformation sequence, you briefly see images of a woman resembling Cenes as the RVR turns into a Rynex variant. The cinematic ends with a font-shifting "Get Ready?" This latter element wouldn't make sense to most gamers unless they played the Sega Saturn version, where the same thing appears in the intro. Vasteel Nocht, which is who you fight, contains past fighters Khaos controlled, particularly the Rynex and the Styx. It's just as possible that it absorbed the core components of Gauntlet. This likely means that, rather self-destructing as her report suggested, Cenes was absorbed by Khaos to form the current ORN Faust. When ORN Faust was defeated as Vasteel Nocht, Cenes reasserted herself to help the player by transforming the RVR-00 into a vehicle that could actually face down the ORN Emperor.