Of course, USPS has been politicized to an unreasonable degree, so folks are reading it in that context.
But the fact that the story was posted by the recipient of the post card, to a Facebook Group, and then only hit the news after going viral means it probably wasn't done by a PR company.
Having done some of this "black hat PR" myself I can tell you that we don't typically cover our tracks that well.
We almost always plant bullshit by going to the news outlets themselves, or paying a blogger to put up an article on BI, Forbes, of HuffPo.
On a completely unrelated note, have you guys heard Amazon is hiring 33,000 new employees with a compensation package average of 150k? Just to help with unemployment during this time of crisis. Pretty cool of them to do that.