HFT / Fund guy here.
This is marketing spiel.
If you just want to trade on a bunch of exchanges so no information flows between them, you can easily (TM) write a program that either a) lines up the orders at each exchange to execute at a specific time or b) delays the orders from a central server by the line delay.
So say NYC is 13ms from Chicago. You want to hit both at once. As long as you're not 13 ms late, nobody can see your order in one place and react at the other. You don't need an atomic clock for that, NTP will do just fine.
They're doing this because they have a reputation as a technologically advanced firm, and they know it will impress institutional investors, most of whom are still living in a time warp where spreadsheets are an advanced means of getting an edge over the market. They meet these guys, who are basically from another dimension of investing, and they suddenly need an explanation to their bosses of why RT can generate the most impressive returns of any strategy ever. The answer is "we have loads of PhD math geniuses building the strategies and amazing execution technology".