A 10Tflop PS5 in 2018 would most likely mean PS would have to change their physical console style. The small sleek box would have to go by the wayside and make way for an XB1 sized box, and whether or not you could use an internal power supply based on the power draw and heat in a system like that, is questionable.
For PS to make this type of change and launch PS5 this quickly, Scorpio (and/or XB1S) would have to sell much much closer to the numbers PS4/Pro has, month after month going forward. This is highly unlikely, especially based on everything XB and Phil has been saying, unless they are lying and hiding a few game changers up their sleeves.
A late 2018 PS5 would have to be $499+, for more reasons than just the 10Tflops. It also could not, in any way, leave the PS4 ecosystem behind that soon. As long as Scorpio and XB1S continue to sell considerably lower than PS4/Pro, which is the most likely outcome, than its in PS' best interest to hold off PS5 until 2019/2020.
PS1 - ! - We must build a console that can alert our enemies.
PS2 - @- We must build a console that offers online living room gaming.
PS3 - #- We must build a console that’s powerful, social, costs and does everything.
PS4 - $- We must build a console that’s affordable, charges for services, and pumps out exclusives.
PRO -%-We must build a console that's VR ready, checkerboard upscales, and sells but a fraction of the money printer.
PS5 - ^ -We must build a console that’s a generational cross product, with RT lighting, and price hiking.
PRO -&- We must build a console that Super Res upscales and continues the cost increases.
