So the employer has a financial inventive program to encourage people to stay in the organization long term, and some hyper-rational VP repurposes that reward as a kind of tenure cliff forcing people out just ahead of it? All the pieces are in the article, just waiting for folks to put them together.
If you're someone considering moving to a company that aggressively uses "performance management" like this ... the target of this system is you, not because you're bad at you're job but because you're new. The human toll of people in positions of trust essentially gaslighting their colleagues about their performance to confiscate special comp or satisfy the gods of analytics.... Deeply misanthropic.