It occurs to me that if you're in a cabin without a balcony, all of your air is circulated through the ships central HVAC system. So, if someone is sick and coughs, there may be a slight probability that the particles they shed may make it to another room through the ventilating system.
It also occurs to me that everyone is being fed through trays delivered to the cabin door. No matter how hard cruise ships try to sterilize the kitchens, every month or so there's a mass outbreak of norovirus. Couldn't food be a transmission vector for this virus, too?
Also crossing this mind ...
Maybe some cabins are vacant when someone goes to the hospital due to testing so.
Some of those cabins will be balconies. Do you want to upgrade from an inside cabin to a outside cabin with balcony ? Knowing the previous occupant is so infected.
Decisions, decisions.
Should I stay inside or should I move to upgrade.