TSMC just announced it has started volume production of it's 7-nm FinFET node, with "over a dozen of customers with tens of designs" using it. That means you will see 7-nm products en mass later this fall, including as mentioned above Apple's latest A12 SoC. However, both Sony and Microsoft usually like to wait a year or so for issues to work themselves out before switching to a new process. So here is what I think is going to happen:
Feb. 2019 - PlayStation 5 announcement
E3 2019 - Major PS5 push, last of super PS4 exclusives shown. PS5 price & release date announcement
Sep. 2019 - PS4 Super Slim and PS4 Pro Slim announced, both with price drops
October 2019 - PS4 Super Slim using 7-nm processor released at $199 with 500GB HDD
October 2019 - PS4 Pro Slim using 7-nm processor released at $299 with 1TB HDD
November 2019 - PS5 using 7-nm processor released at $399 with 2TB HDD
That would create a pretty unbeatable lineup going into holiday 2019.
