US Government employees basically can't sign non-disparagement agreements, the Federal Government doesn't enter into agreements without a fixed time commitment to judge compliance, and there are incredibly strong whistleblower protection laws for Federal employees which would make any non-disparagement agreement very difficult if not impossible to enforce. A Federal judge held that the Trump 2016 campaign's non-disparagement agreements were unenforceable, and there have been no hints of Federal employees being offered anything even like that.

That bit of pedantry aside, I agree with you that the purpose is to draw attention to something bad happening, it is a grander version of leaking to a reporter.