CTL >> If the offer is refused, the former employee loses benefits
This is not easy to do for any sensitive position. So, you are getting unemployment claim from someone who just quit. You send him a job offer and he accepts it and comes back under duress. I would not want this employee in my office.
Halachik aspect: we are supposed to treat employees with some leeway to make sure they do not feel enslaved (i.e. be not in control of himself and his time). For example, employees can leave on a spot and you are not supposed to force him work further. This offer essentially forces him to work.