2016 town and country trasmission is it sealed?

It's not a sealed unit but it also does not have a dipstick, requires a special tool to check or add fluid. Dealerships are moving away from letting customers maintain their own transmissions, as too often they check fluid levels at the wrong temperature, and inadvertently add too much or too little fluid. Check your owner's manual about the maintenance interval for your vehicle, you shouldn't have to touch it until then.