Just a few months ago it came to light that managers at Amazon hire new people they're planning to fire shortly after, so they don't have to fire people they're attached to in order to meet such a quota.
A few years ago there was a lot of noise about stack ranking at Microsoft, and there was also a lot about people crying at their desks at Amazon several years ago - perhaps you're remembering one of those. I believe the specific "hire to fire" press is pretty recent.
I remember hearing about "hire to fire" at Amazon as far back as 2014, though the claim was that it happened "merely" enough to have a cute name, not that it was endemic.
https://www.businessinsider.com/amazon-tracks-unregretted-at...