Again thats still taking the Xeons (SKL-X are already Xeons, they are all mesh, the original rumor was 10C SKL-X was ring bus LCC and 12C+ Xeons MCC or HCC, thus an emergency addition, wrong they are all server mesh cpus, they are all xeons), validating a 12 to 18C cpu in a socket designed for 10C max, moving the production schedules of SKL-X, CFL-S and Xeon to fit the SKL-X +12C, in the time-schedule that was originally intended for SKL-X in the first place. If they managed to do that is at minimum amazing.
And for what? is not needed, they had the Xeons to fight TR in high end workstations, like it was with BDW-E and before.
Just face it, this rumor died the day "September launch" was know, everything leading up to this rumor turned out to be fake. The only thing you have are the old pre-release leaked slides and they may not be accurate to start with. How many pre-release slides had errors or were compeltely fake before the launch of X product?
There was never any rumor like that. The rumors or better said actual slides like the one i linked dealt strictly with core counts. There was no mention of MESH until maybe 2 months ago:
http://wccftech.com/intel-skylake-x-skylake-sp-mesh-architecture-interconnect/
Just for the recapitulation:
Intel originally released info, which pointed toward the possibility of 10C being the top Skylake-X consumer part. Its on that previously linked slide.
Later, rumors came up, that the top HEDT chip will actually be 12 cores, not just 10C. This was reinforced by this photo:
This is the first mention of 12 core Skylake-X part, although as you can see, its properties were unknown yet, which kinda makes it look like afterthought, not surprising given the original Intel slides.
At this point of time, there was no talk about LCC and HCC and whatnot, this stuff came into light later when the whole line-up up to 18C was revealed . There was a bit of confusion, whether 12C will be still LCC, or already HCC, which was later definitely put to rest with the Mesh info.
Finally the Computex slide:
Threadripper was officially mentioned by AMD for the first time on 16th May, 2 weeks before Computex.
http://www.amd.com/en-us/press-releases/Pages/amd-unveils-expanding-2017may16.aspx
this is how it all happened to my knowledge. You are free to dismiss it as fake.