6 TFLOPS is to 4.2 TFLOPS what 1.84 TFLOPS is to 1.3 TFLOPS, so I don't understand why PS4 Pro is launching this year while poor Microsoft will have to wait until the next.
6 TFLOPS is not all that special if people will have had a whole year to get their eyes used to 4.2 TFLOPS. The Scorpion already is beginning to sound underwhelming, relatively speaking.
Scorpion's only chance to stand out at least a little bit is to up the specs to 8 TFLOPS and include the brand new Zen CPU from AMD.