This is just a means of doing layoffs without needing to pay severance or unemployment while automatically filtering for people who are less invested in the job, isn't it?

This is a form of constructive dismissal.

Oh can they Amazon? Can they quit their jobs? Gee, how benevolent of you to put them between a rock and a hard place.

Just don't comply with the rule. Sure they will eventually fire you, but you can spend that time looking for a new job. Don't just hand the downsizing to them, make them work for it.