Similar to changes at Walt Disney World, Disney Cruise Line is replacing Do Not Disturb signs with new Room Occupied Quiet Requested door hangers. It is unknown why this is being done on the ships, but it was a result of security concerns here in Orlando that prompted the change following the mass casualty event last year in Las Vegas.
The change is being rolled out today beginning with the Disney Dream.
Disney Cruise Line reserves the right to enter your stateroom, even when this sign is displayed, for maintenance, safety, security or any other purpose. The ship’s Crew will knock and announce their presence before entering.
To my knowledge, there have not been any onboard incidents that have triggered this change on the ships. It would appear this is just Disney Cruise Line following in the footsteps of Walt Disney World. It should be noted, that stateroom hosts typically enter the room at least twice a day for morning clean up and evening turn down service.