The company letting a manager relay a message, with any censoring, is certainly better than the person having no way to get their contact info to people, and they might also say something nice for morale.
My suggestion was meant as something that's feasible even for a company that already got burned by vengeful leavers; and also something that an individual manager has an easier chance of pulling off, without having to change all of corporate policy.
I told them that I really wanted to finish the work for a customer (large state organization) because I liked the customer. They let me stay for a week.
Of course that was bullshit, I took the time to have back channel communications with the customer to see if they would hire me as an independent consultant after I left and to start interviewing.
I’m sure they would have. But I gor a full time offer less than two weeks later.
I knew after the first year that I didn’t plan on stay at Amazon for more than four years and I planned accordingly.
I was nine months and two vesting periods short. But the severance more than made up for one.
The longer version of the story.
It's not good practice for all situations -- you need some trust, despite the stressful situation, when people tend to show character and weaknesses -- but in this case, it worked out.
The departing employee posted a message of encouragement to the remaining people.
Kind words and contact info were exchanged, etc.