For gaming Threadrippers with their 2019 Zen2 architecture are slower.The low-end Threadripper Pros are relatively cheap, with the 16 core costing under £900 if you know where to look, so the 12 core 3945WX should be a lot cheaper (though I can't immediately find UK stock). And Threadripper Pro CPUs - unlike Ryzen (and Intel's Core range) - don't have the problem of severely limited PCIE lanes. Likewise a WRX motherboard isn't that much more than the board he originally listed. And then there's the upgrade path.
X570 gives plenty of I/O for gaming.
And doubt there's upgrade path to any newer architectures than on AM4.
In fact HEDT's job in more heavily multithreaded workloads and multitasking is more bandwidth requiring then desktop and would benefit more from extra bandwidth even at the expense of latency.