I'm calling BS on that leak. For one, I can't see Sony aiming for $500 instead of $400. Secondly, no way Navi's highest end chipset is 14 tflop, it is AMD's next-gen mid-range GPU line, replacing Polaris. The current highest end Polaris GPU is 6 tflop. No GPU ever has more than doubled the performance of the previous gen chipset it is replacing. 10 tflop is most we can expect from Navi I think, maybe 11 tflop if Sony runs the clocks pretty high.
I remember reading that the PS5 and next Xbox are gonna have more teraflops than Stadia's 10.7 from an insider after Google had their reveal. I think 14 teraflops might still happen but im not as well versed on computer specs as you so you might be right.
From what Sony announced today I dont see how they can sell the PS5 at $399.
For one thing, I wouldn't be expecting the SSD to be the primary means of storage. I have a feeling we're looking at a much smaller SSD drive used for caching purposes. An SSD large enough to hold a decent number of next-gen games (most next-gen AAA games will be topping 80 GB most likely, with some over 100 GB, considering some current gen games are like RDR2 are already pushing 100 GB) would simply cost too much to be feasible for any next-gen console, especially since Mark said that the SSD is blazingly fast, hinting at an M.2 SSD.
I'm thinking maybe it will have a 64 GB SSD, maybe 128 GB, paired with maybe a 1 or 2 TB 7200 RPM hard drive. When changing games, key files would be quickly written on SSD, with the less important files pulled from the standard hard drive. The initial load when first changing a game would be fairly long still, but all subsequent loads while actually playing; respawns, fast travel, etc. would be way faster, like the 0.8 second fast travel time in Spider-Man that Mark demonstrated.
Using a smaller SSD for cache would greatly cut down on the price.