Spark plugs blowing out of cylinder heads has been a notorious problem with Ford's modular V8 engines, though by 2013, Ford had addressed the original design issues. If you're experiencing this at 200,000 miles, worn threads or improper previous service may be the cause.
History of Ford Spark Plug Issues
Early 4.6L and 5.4L Triton engines had only four threads holding each spark plug - far too few. Ford redesigned the heads with more thread engagement. Your 2013 F-150 has the improved design, so plug ejection shouldn't occur from design flaw alone.
Why Plugs Eject at High Mileage
Previous overtightening may have damaged threads. Incorrect plugs may have been used. Prior thread repair may be failing. Corrosion has weakened the threads. At 200,000 miles with many plug changes, cumulative thread wear is possible.
When a Plug Blows Out
The explosive sound is unmistakable. The engine immediately develops a misfire. Coolant or compression can damage the coil and wiring. In worst cases, the plug damages the hood or other components. Stop driving immediately - operating on remaining cylinders causes catalytic converter damage.
Repair Options
Thread repair inserts (Time-Sert, Heli-Coil) install new threads without head removal - $500-800 per cylinder. Severe damage may require head removal for professional machining. Prevention through proper torque and anti-seize compound is critical for remaining cylinders.