Conspiracy theory

That's probably correct.

My airport is JUST outside the Washington DC SFRA (Special Flight Restriction Area) so I get to hear "TFR Ahead!" on almost every takeoff.

Foreflight has always displayed the SFRA as a 25-mile radius shaded in red, but recently it started showing another, 50-mile radius circle shaded in a lighter shade of red. I called Center asking about the mystery TFR and they said they'd been getting a ton of calls but not to worry, the 50-mile radius is a 250kt speed limit above 18,000 ft.

That's despite the fact that I have Foreflight set to ignore things above 10,000ft and it had always done so in the past. I think it's possible that after a few recent incidents and busted political TFRs, Foreflight has changed their settings to show ALL the TFRs even if they're outside your limits.

I suspect it's a case of ForeFlight being "enthusiastic with their NOTAM display. Searching for that specific NOTAM on the FAA site brings it up, but neither AOPA FlightPlanner or Skyvector display that one. Currently there are very few TFRs displayed, either pending or active from what I can tell. Perhaps I am scrolled out too far? Even zooming into the Wichita area doesn't pull up 01/977. From its description I suspect some form of testing by the manufacturers located there. I too don't have a lot of trust in government but don't think there is any hidden agenda with the hard to find TFRs.

I don't use ForeFlight but I don't see any widespread exercise areas on AOPA'a flight planner. Also the dates you show indicate this has been in progress since the first of this year, and if so, there would have been some form of leak in the "news" by now. I suspect an anomaly in ForeFlight.