You've misinterpreted whatever it is that led you to think you know how the antenna should be connected. If you search the Internet you will find documentation that explains how to use it.
The antenna as Molex have designed it is meant to be stuck on the inside of of a non metallic enclosure of some consumer product that needs to connect to WiFi.
Pure coincidence? Do you honestly believe that it was designed to connect to pads on the Giga by pressure alone?
Did it never occur to you to wonder why there was a connector on the end that you weren't supposed to use? And why Arduino put the mating connector on the Giga PCB?
