It absolutely is callous, “showing an insensitive and cruel disregard for others”. It is not financially callous, as you point out, it absolutely is emotionally

It absolutely is callous, “showing an insensitive and cruel disregard for others”. It is not financially callous, as you point out, it absolutely is emotionally callous to not have the courtesy to even notify the person that they are ending the employment, and not giving them a chance to say goodbye to their colleagues. Regardless of whether you see work as your primary community, suddenly being suddenly exiled from a community is hard. Its even worse than treating relationships as transactional (which is also callous), it’s switching someone’s status from in-group to out-group unilaterally and not even telling them. Like if you found out your spouse was leaving you because they changed the locks on the door—but, hey, it’s all good because they’re giving you a year’s worth of their salary, right? Sure, it could be worse, but that doesn’t mean it isn’t callous.