Earlier quoted context omitted.
Or maybe, juste maybe, that's when they started testing…
Wayback machine has nothing for this site before today, and article is "last updated Jan 29". A benchmark like this ought to start fresh from when it is published. I don't entirely doubt the degradation, but the choice of where they went back to feels a bit cherry-picked to demonstrate the value of the benchmark.
If anything it's coherent with the fact that they very likely didn't have data earlier than January the 8th.