That is just Intel grabbing some attention from the Threadripper 32 core announcement. It doesn't run at 5Ghz, that was heavily overclocked using a custom cooling system hidden under the table.
So sure Intel can make 32 cores go fast, by taking a $10,000 chip (literally, it's a relabel of the Intel Xeon 8180), a giant power supply, impressive cooling, and a 735 watt pump. Still only has 75% of the memory bandwidth/memory channels of the AMD epyc.
My main hope with threadripper is that they hit the lower price points that the HEDT intel chips do (I.e. $300-$500).
1900x sells for ~$450. It's just the 8 core part, though — might as well grab the Ryzen 8 core for way less cost instead unless you need the memory b/w or PCIe lanes.
i7-7800x (Skylake-X) is a sort-of last gen part (Kabylake-X briefly existed in the form of i7-7740X, although only in a 4-core SKU); 4 GHz is its maximum turbo clock (may be only single core); base clock is 3.5.
1900x is current gen, although about to become last-gen; its base clock is 3.8, 4.0 turbo (single core).
Same number of memory channels. 33% more cores. AMD's IPC lags Intel a little bit, but not by 25%. Is it worth the $60 (15%) premium? Maybe.
When TR2's version of 1900x comes out, TR1 1900x may experience a nice price drop, making it (even) more competitive/affordable.
A bit of Googling verifies that you are at least partially correct: "Intel announced that it is releasing the Core i7-8086K, a special edition processor that commemorates the 40th anniversary of the 8086..." and "...reports speculated that Intel would only produce 50,000 units. Our sources have confirmed that this is a limited-edition chip, so Intel isn't positioning it against AMD's competing Ryzen processors."