How do I know? Whenever anyone produces any kind of benchmark, the burden of proof is on those who produce the benchmark to establish that the resultant figures mean anything. Without providing source code or any points of reference, the CPU-z bench was basically just . . . numbers that sort of fell in line with how fast we expected CPUs to be relative to one another.
When I run y-cruncher, I can go to the website of the guy who maintains it and get a fairly-detailed explanation of the algorithms represented in the code. Hell you can even narrow down exactly which ISA extensions are used by the code modules. When I run something like Cinebench, I can see what the program is rendering, even if I can't see the underlying code of the render engine. I can still see what it's doing, more or less.
The CPU-z bench just spits out numbers. That's it. Maybe now they've gone to the trouble of describing the bench a little better, and if so, that's great. But it still doesn't explain why the old version of the bench had to be replaced by something that doesn't run as well on Ryzen.