Your specific agency head telling you want to do in a signed statement-Ok, that is my job.
A random unsigned email from "HR" at another agency that looks just like all the "phishing" tests they send all the time directing you to send information to them that you already share with your supervisor at your specific agency. Yea, sorry, MAGAs love it, but it is fishy. I did it after my agency told me to, and it isn't hard. You can try to pretend this is standard, but it isn't.
If they want to be an official part of the "government,"put out a directive that we are to follow orders from "X" have "X" sign the damn emails. This is basics of leadership crap, and they are failing.
But, the truth is they did not want to put it out as an official appearing directive so that the vast majority of Federal workers would just do it. They wanted it confusing and strange. That way, we show our concern, people like
@Rob B. can make fun and they get the division of people that this administration clamors for.