There are a wide variety of factors which can prevent or cause the screen to break during a drop.
Historically the QC done by Corning on their glasses has never let out of the factory weaker than spec screens.
It is quite unlikely that there is a batch of glass which is quite weak.
From my point of wiew that article is a clickbait just to get some wiews like those who come out every day about "a new battery tech which will revolutionise smartphones" and after 10 years and thousands of new claimed battery techs here we are with only li-ion and future graphene solid state batteries.
Anyways I had a look at the video in the article, he is dropping the phones from a pretty good height with the inertia of the clamp and the phone and he is dropping on gravelly like concrete. Basically it is the worst case scenario ever. I highly doubt that any kind of glass would survive to such a drop. Stupid article
The "article" is stupid period.
"We took an s21 ultra and slammed it on grainy concrete flat down without protection and it broke, it may have been a defective screen." Basically this is the take of the article and it speaks for itself about how much it is nonsense.