I’ve figured some things out about this.
You can turn off the part of the device that connects to cell networks, so no biggie there - you can use it just fine in the plane. My second question was, okay, so now you’ve turned off the cell communications part - does the Bluetooth networking for games still work? Yes. Yes it does.
What have we learned? That I was right, and Gabe was wrong. About playing on planes, at least. That’s hardly the only difficulty faced by the machine.