I am baffled by this. Are all these people trying to figure out how to announce that an employee is leaving? If so, the answer is: Be straightforward. For example: "I'm sad to announce that Julie has decided to move on and her last day with us will be August 30." Then you say some nice things about her if you can (about her work and achievements), and add that you wish her the best. And you can think about what things people might be wondering about (timeline for hiring a replacement, who will cover her responsibilities in the interim, etc.) and address those things too.
If the employee was fired, the format is pretty much the same, although shorter: "Unfortunately, Julie's last day with us was today. We wish her the best of luck, and we'll be moving quickly to hire a replacement. If you have questions about projects you were working on with her, please see Jeff for updates."
Does anyone think this is not as straightforward as I'm alleging? Tell me what it is that is tripping people up about this.
P.S. I may do a week of posts addressing some of the search terms people are searching for here. Does that sound really boring?