The federal government is not his company.
And while the majority of agencies are under the executive branch, so Trump DOES have obvious power there, it's still not like the government is his property and we work solely at his pleasure. We didn't swear an oath to the President, we swore an oath to the Constitution. It is explicitly ILLEGAL to threaten a non-probationary employee with essentially involuntary resignation the way that email did. Not sure how legal it is for probationary employees either, but unfortunately, they are less protected.
None of which suggests we somehow CAN'T create such a list. Of course we can. I send my supervisor a DAILY list of my tasks in my logout email. But I send it to my supervisor. As you do. DoD or otherwise, we are not supposed to go outside the chain of command like this.