No it isn't? PS4 is 1.84TF so 10X would mean 18.4TF.
I think it much more reasonable and realistic to expect 11-12TF tops for PS5 in a sooner rather later launch i.e. 2019/20. PS4 Pro was 3 years after PS4 and was a 2.3X boost even with a full node shrink. 3X that for PS5 with a proper new GPU architecture, new CPU and say 16GB of really fast RAM (GDDR6?) after another 3 years (2019) seems perfect to me.
Launch at the aggressive $399 price point and see it fly off the shelves.