NB: I still think this is fake.
No way did AMD decide in 2015/2016 they the were going to have two Zen+ non-APU dies.
7nm insurance design.
You have your 7nm design, you go all out on this - 8 core CCX, 16 core dies, 64 core Epycs.
But ... in 2016 and 2017 AMD didn't know that TSMC would pull through on their 7nm promise in H2 2018. But they needed Epyc 2 by Q1 2019.
So you design a 12nm backup. You have power and die size issues here, you cannot go all out like with the 7nm design. So you go for a 6 core CCX, 12 core dies, 48 core Epyc 2. This 12nm was likely taped-out and probably had some silicon spun.
This fits with some rumours that it would be 48C initially.
But then GlobalFoundries tell you they won't be doing 7nm (initially this was probably a strong hint, or saying it will be late, or similar). Or TSMC say that Apple bought all the space. Result: your booked Zen 2 runs at TSMC cannot cover all of your product need for consumer space.
7nm consumer Zen 2 is put back, H2 2019 say. Not a disaster to wait that long really, but right now, Intel is hurting on their 10nm process, and don't you just want to stick the knife in?
And you have a 12C Zen or Zen 2 based 12nm die, and you also need to make stuff on GlobalFoundries because of wafer agreement. And you also want to have something to compete in some metric (i.e., multi-threaded performance) against Intel's 8C consumer chips coming in Q4.
So you leave a space in your line-up just in case you need a 2800X later in the year. You get a thousand wafers of your new design fabbed, you fuse off some of the Zen 2 features for next year's products. You package up the samples and send them out to OEMs and partners.
Given that timeline, I'd expect to see initial leaks happening right about now.
NB: I still think this is fake.