Ryzen 3000 CPU and GPU are 7nm
Will Ryzen 3000 APU be 12nm?
Why are they so much out of sync?
AMD has switched up their CPU development roadmap. From 2013 to 2016, they became an APU company, selling products like Kaveri, Carrizo, and Bristol Ridge as their main product. Now those products are on the back-burner.
AMD's current pattern is to emphasize product in the following order of prorioty:
EPYC (Server) first - Rome is first out of the gate on 7nm
Ryzen (desktop) second - Matisse is second out of the gate on 7nm
Threadripper (HEDT) third - Whatever is their internal codename for the 7nm HEDT will probably follow somewhere in Q3 2019
Ryzen mobile (low-end APU) last - 2019 will see 12nm Zen+ based APUs, under the broad name of Picasso. They will aim at mobile and low-end desktop, with very little emphasis on cheap AM4 solutions.
We probably won't see 7nm APUs until 2020.
This is the reverse of how they used to be pre-Zen, where they were first to market with APUs and launched pretty much nothing elsewhere.
The confusion is that 3000-series APUs will be 12nm Picasso while 3000-series CPUs will be 7nm Matisse. If WCCFTech is to be believed, AMD may put Matisse under the 300-series monicker, so instead of having things like the 3800x or 3850x, we'll have the 380x and 385x. That will leave the 4-digit 3000-series numbers to Picasso.