So, the US Capitol didn't think to ask the ATC why there was a plane there, considering that's the purpose of the ATC? That seems even less likely.
My naive assumption is that one of the main purposes of these organizations, that we spend an incredible amount of money on, is to create, ready, and follow clear processes. What the heck are they doing with all that money/time? Does all this get reset with every election, or something?
Not only was ATC informed... you could go on public websites like adsb exchange and see exactly who the plane is.