According to the parts diagram, it says the "Oil Drain Plug, Including Gasket."
I would be surprised if it is a copper crush washer. I just did the oil in my 2018 GMC Canyon and it uses a rubber gasket that seats into the rim of the plug. The GM parts diagram shows the rubber gasket and I get them at Napa when I replace my oil but the Ford diagram for the V10 does not show a separate gasket.e
When I go to Autozone's website, it does show the rubber gasket for the oil drain plug. It looks just like the GM one.
There is no way it would fall out on its own. I have to take a small flat-blade screwdriver to remove it.