The APUs announced at CES (codename Picasso) will get the 3rd gen Ryzen branding but will be on Zen+, the APUs won’t be “refreshed” with 7nm until Renoir comes about. Which I expect we’ll start hearing more about very late this year or early next year. Expectations are that these will share a similar layout to Matisse(desktop CPUs 3rd gen Ryzen) but replace one of the CPU core chiplets with a GPU, although time will definitely have to tell on that one!
The APUs previously on sale were “plain” Zen while desktop CPUs were at Zen+, the APUs on sale while “plain” Zen was the main desktop CPUs were Excavator/Bulldozer based still. So yeah. The APUs lag about a year behind the desktop parts as far as process goes, but still have the same generation branding as the desktop parts.
EDIT: Well, I say a year, but considering the launch of 3rd gen Ryzen will be “mid 2019” it’s more like 6 months. And the same would be true for previous desktop and mobile parts really.