You're fine, Andy. Gas-pressurized shocks will expand when they are unladen, but not all shocks are gas-pressurized.

The dampening of any shock is provided by the resistance of the oil to flowing through a narrow-diameter hole, and that hole size is adjustable on an adjustable shock like the Rancho 9000. But the gas pressurization does not really provide the dampening in the shock (although it does provide a little, I guess), nor does it provide any positioning of the car on its suspension - the spring does that, and the shock only dampens the motion of the spring.