Garcetti v. Ceballos. That's the case I was thinking about. I just had to crank out a big paper ex nihilo and just polished off a final so I apologize for not recalling the exact citation.
Turning in your budget paperwork in response to the interagency demands of the OMB counts as official action as part of official duties. It wouldn't be in my duties at my measly GS-7 pay grade (scale runs GS-1 at the bottom to GS-15 at the top) but the senior execs would have such in their duties.
The ban in the WaPo article only related to the budget paperwork. That's all OMB could control. It does make me wonder what somebody CDC wrote.