That AMD has been going insanely strong with many-core processors is not a surprise, you've read all our Threadripper reviews and have learned that the top tier processors (e.g. 32-core versions) have four dies each holding 8 CPU cores. So what does the future bring? Well, how do 64 cores over eight dies sound?
The chatter at the moment is based on an 8+1 version block diagram spreading on the web, with 8 dies and 8-cores per die you are looking at 64 cores and 128 Threads. Obviously, that kind of design would apply towards AMD Epyc2 processors or even later revisions. The extra (middle) die is intended for a dedicated system controller chip.
The dies would all be connected over the infinity fabric with a dedicated system controller. This new rumor was derived from ComputerBase who noticed information from SemiAccurate plus sketches that an engineer has put on Twitter. In his own words, these sketches are his interpretation of how AMD would build the upcoming server processors. Backtracing the twitter account I noticed that the block diagrams have been posted by K.H. Chia, he is a retired engineer. So if this is just an example showcase present to AMD or not, we cannot verify. So how true or false these new design sketches are, remains to be seen but for now I rate this as some speculation at best. The architecture is listed as Rome.
If AMD shrinks the dies towards 7nm next year, effectively they have a die half the size of what it currently is. More dies would fit on the same surface. Placing a chip in the middle that is connected to all the CPU-dies could result in less latency than in the current design where the ccx's are interconnected via the Infinity Fabric.
AMD has officially not yet published any specific about the Epyc 2 server processors. The manufacturer has said that the processors are made on the 7nm process of TSMC and that they will become next year.