Couple of things -
Despite having an oil pressure gauge, the sending unit can only register proper pressure or zero pressure. It's an on/off unit. There is no scale of values on the PID like there is for coolant temp, trans fluid temp, etc. So the low oil pressure light does not necessarily mean you have "zero" oil pressure, although it could.
This engine uses a variable displacement oil pump. Ford's response about long idling and oil thinning has a small amount of credence. When idling, the Raptor engine's oil pump will operate on a lower output mode, which reduces parasitic drag and thereby lowers fuel consumption. Although I don't buy Ford's explanation, one possible theory is that the oil pump is not quickly switching back to full output fast enough when you floor the throttle. That would explain how the light goes away after a restart.
These trucks have an engine hour meter and engine idle hour meter. In the diesel world, idling is bad and rumor has it Ford will soon only warranty your engine if the idling time is less than 20% of total hours. Idling a gas engine has less side effects than idling a diesel...but nevertheless, Ford has stated vehicles that idle a large amount must be maintained on the severe service maintenance schedule. Whether that amounts to a 3k mile oil change or a 5k mile oil change I'm not sure, but I have always changed my gas engines at 3k and my diesel engines at 5k. An oil change on the Raptor is what, $40? Very cheap protection regardless of what engine you have. Considering this is a turbocharged engine, and the oil will get hotter under heavy load, and could start coking in the turbos if the engine is shut down after a hard run...3k oil changes are cheap protection.