As pointed out by Tom's Hardware, it's a bit unclear whether these are just die shrinks or a new generation. Previously, AMD implied Zen+/Zen 2 (both names have been used) would be made on the 7nm process so unless something changed this is probably just a die shrink:
We followed up with Papermaster in person and confirmed directly that the company will transition both Vega GPUs and the Ryzen line of processors to the 12nm LP process. However, it’s still not clear whether or not he meant that 12nm LP will be a shrink of Ryzen in 2018 (a "tick" equivalent if you will) or if Zen+/Zen 2 will also be using the 12LP process. Previously, AMD has implied that Zen 2 will use the 7nm process. The company has used both "Zen+" and "Zen 2" to refer to its next-generation die.I dug up some AMD roadmaps from May and these do indeed show Vega and Zen on "14nm" and "14nm+". This implies 12LP could be what was previously known as 14nm+.
GlobalFoundries expects to begin 12LP risk production in the first half of 2018 so don't expect to see these chips right after New Year. Current Ryzen processors are made on the 14LPP process but unfortunately Globalfoundries didn't seem to share details about how much better 12LP is versus its own 14LPP.
All we know from the slide below is that 12LP offers 15 percent improvement in circuit density and over 10 percent higher performance than "industry 16nm FinFET solutions". All these names are just marketing of course and 12LP is just an improved version of the 14nm node.
AMD CTO Mark Papermaster announces support for @GLOBALFOUNDRIES new 12LP. This is a roadmap improvement from planned 14nm+ to 12LP. pic.twitter.com/BVEOZiEdKh
— Patrick Moorhead (@PatrickMoorhead) 20 september 2017