While AMD claim it can be overclocked to 4200 or 5133, it doesn't invalidate my claim that officially it is spec'd for DDR4-3200 according to the product page: https://www.amd.com/en/products/cpu/amd-ryzen-9-3950x

Note I am not playing down the 3950X's performance. It is overall a processor superior to Intel's counterparts in most aspects.

Because officially ddr4 is only up to 3200. See https://en.m.wikipedia.org/wiki/DDR4_SDRAM

Every ddr4 module beyond that is officially a 3200 module with overclock option. That's why you need to enable Extreme Memory Profile in your bios to use speeds beyond 3200.

I wonder if G.Skill will release new RAM targeted for Zen 2. Their 3200 MHz FlareX works pretty well with Zen+.

It's G.Skill. They'll release ~100 new SKUs for it, as long as they can get enough well-binned modules from samsung.

That's... literally the opposite of what "supports" means... It works with overclocked memory some of the time, but they don't promise that it will.

The point being that this is a tricked out rig, not an official reporting of the CPU's performance. And that makes the headline essentially a lie.