They don't run that often. When you get on the phone in 9 minutes, just tell them you want 8pm for Illuminations (they will tell you they can't guarantee Illumination, ie if it is cancelled or weather delays your cruise is not automatically extended but not seeing it is rare). They will also call you back if for any reason there is a time change for Illuminations. You'll take a short right first and they don't leave the dock immediately, so 8 is right,
Hope this helps