If those results are true, 5800X3D is a killer Gaming CPU at half the price of 12900K. If DDR5 is used the perf/$ is getting even worse for the AlderLake.
I'm not sure the price matters to anyone who just wants to buy top performance. If 12900K and DDR5 is on top, it won't matter to people who have to spend an extra $800 or more. They probably already spent at least that much on getting a slightly better GPU than the next best option.
The most compelling case is the other one that has been brought up where if you have a specific budget, going with Zen 3D/DDR4 let's you shift a lot more of that budget to the GPU.
But at the end of the day it will be a halo product to get AMD more mindshare with the general public. Most gamers are going to end up choosing between a 5600 and a 12400, but maybe these top end parts helps sway average consumers a little bit. Unless you're buying a high-end GPU like a 3080 or a 6800XT, you're not going to be held back by a mid-range CPU. The same goes if you're gaming at 4K or even 1440p in most games. The KS and 3D are both wasted there.
Frankly it just makes me even more excited to see what a Zen 4D is capable of doing or if AMD could create an insane APU with v-cache that's accessible by the GPU.