If you look around you'll see people already putting the new, chinese made DDR4 through its paces, it's holding up far better than anyone expected.
Every single time I've had someone pay me to figure out why their build isn't stable, it's always some combination of cheap power supply with no noise filtering, cheap motherboard, and poor cooling. Can't cut corners like that if you want to go fast. That is to say, I've never encountered "almost ok" memory. They're quite good at validation.
The danger is we’ll start to see more QA rejects coming into the market. The temptation to mix in factory rejects into your inventory is going to get very high for a lot of resellers.
If we had a time series graph of this data, it might be revealing.