Open a low point drain and a faucet to find out if there is pink stuff in the lines. If there is, it will run out the open low point drain when you open the faucet. If pink stuff runs out the open drain, open the other low point drains and faucets to finish draining. Also open the fresh tank drain and water heater drain to see if there is pink stuff in there.
If nothing runs out the open low point drain, then it was just winterized with compressed air. Close the low point drain you opened and check the others to make sure they're closed, close the water heater drain if it's open, and close the water heater bypass valve. Also make sure the fresh tank drain plug is in place.
If the van is brand new, you should disinfect the fresh water system while dewinterizing, before using it. Also if the fresh water system has been left open to outside air (water heater drain plug out, fresh tank drain plug out, low point drains open, etc.). An open freshwater system can get contaminated; a closed system can't. Your Airstream owner's manual will tell you how to disinfect the system.
Engineering: Finding complex solutions to simple problems you didn't even know you had.