If PHB has to go, it'll be described as "Dear employees, to our great sorrow Mr. PHB has chosen to pursue other exciting opportunities with another firm, therefore we agreed, by way of mutual consent, to bring this glorious success story to its last epic chapter".
When a non-manager has to go, it's: "As you all know, Mr. Dilbert has brought down the network last week, and this adds to some other failures, the rumors of which have probably reached you by now".
So yes, it's different- managers are allowed to be people, while employees are only a resource.
The dialog in Dilbert strips uses a unique convention; as we all know the characters frequently say exactly what they're thinking rather than giving a less-informative but polite reply. I've always supposed, particularly in the Boss' case, what we're reading as his dialog is not what he actually said, but how others interpret it. This is one of the outstanding features of the Dilbert strip, and I don't know of any other strip that uses it. When I see it happening, I really feel at home and I *know* this is Dilbert-World. The real world should be so good. Thanks, Scott!