If the employees are happier and more engaged, can we assume they are salaried and not paid hourly? In which case, we are already talking about the minority.
The vast majority of people work for an hourly wage, which makes me think they will either lose a day of pay, which will not make them happy — or will have to work longer days to compensate, which will also not make them happy.
For a corporation, this would likely be a boon. More part time workers means less benefits to pay out. Can’t see how it would benefit anyone but salaried workers, though. Did I miss something?