Incredible little detail. I'm pretty sure I have a bunch of disks with similar issues that I couldn't diagnose because I'd never consider this a critical failure point.
Not many of us buy disks at enough scale in order to see patterns emerge from their failures.
I personally have like maybe 5 disks, two I purchased and three scavenged from systems they outlived. Not really gonna learn which ones are good and bad with that kind of sample am I?