Legitimately asking: Do you have any evidence that this achieves certain goals better than how this email was phrased? Are you sure those goals are the same as those of the author of this email?
Judging by the contents of this email: the goal might be to confound or confuse counter-arguments to the decision, limit the damage PR-wise (and stock wise), and above all, insulate the new executive staff from a groundswell of anger/hatred from the bottom.
My instincts as a writer, and maybe a bit as a human being, is that you shouldn't try to fool the people who support you. If the author of the email (probably not Dorsey) was a stronger writer, and perhaps free of some pressures, I'd like to think he or she could have both been fair to those under him or her, and also protected from their wrath.
I too would be very interested in seeing historical examples of leaders forced to write messages explaining tough decisions. Would you happen to have any?
The goal is for the employees to feel as if you ARE being honest, and that they have something positive to focus on that is not just plain disappointment and insecurity.
Plenty of corporate drones take this too far and focus too much on the sugar-coating to the point that only other top corporate drones think the email is a good one.
But I think Dorsey's passes the b.s. test (Most people's reactions, even those being fired isn't going to be "what a load of b.s.")
Could he be more direct? Yes. But it would come at a risk of coming off as callous and incosiderate.
Unfortunately I can't figure out what books I read and I'm having a hard time finding studies (just keep finding damn buzzfeed like article about using the sandwich). If someone else finds these sources or debunks them I would be greatly appreciated :)
Then he rewrites it focusing on what the person reading it is concerned about: themselves. The key was to focus on the questions a reader will ask, "How will this effect me?" and "What should I do?"