Likely any benefit is a cognitive dissonance type effect. The article says that only 2-3% take the offer (so not much of a filtering effect) and that while you

Likely any benefit is a cognitive dissonance type effect. The article says that only 2-3% take the offer (so not much of a filtering effect) and that while you would think people would come in and abuse the offer HR doesn't seem to have a lot of special pre-screening. So likely the idea is to get the new employee to value the position as the internalize the lost value of the money they just turned down to continue the position. Not so much filtering people as attempting to nudge them a bit.