You're assuming Moore's Law shrinking will continue. I don't see any evidence that companies other than Intel will successfully get past 22nm-class tech (aka "Samsung 20nm" and "TSMC 14nm", which are misleadingly named)
Even what's on the roadmap for the other foundries doesn't make any cost savings via reduced density. The demand is all about reduced power consumption for mobile form factors. These processes are not suitable for high performance chips like PCs and game consoles.
In 2019, we will not have seen sufficient progress to get 16 CPU cores in a console, unless they are inferior to the current cores. There's only one performance CPU company left in the world, and it doesn't have enough competition to make more than minor improvements from now. RAM pricing won't have come down enough to make 64GB feasible. I expect 16 or 24. And graphics power consumption won't have come down enough to put a chip in that's both 4K and 60fps, never mind 90/120.