CyberPowerPC is doing the 4x8Gb for the looks of the 4 sticks, not for the performance.
That pc is vastly overpriced, unless you are extremely serious about OC, you don't need the Formula, the Hero does just as well at half the price. And 16Gb is fine for gaming, not many games even hit @12Gb total system memory, and thats pushing sli 1080tis in 4k. Most games average 4-8Gb. Only real reason for more than 16Gb is fro production usage or Virtual Machines, and even then 32Gb is seen as an absolute minimum, 64Gb or upto 256Gb being more common.