Due to security concerns over the recent years, Walt Disney World started a security procedure on December 22, 2017. It started with Grand Floridian, Polynesian and Contemporary hotels with the intention of expanding this practice over time.
Walt Disney World no longer provide guests with “Do Not Disturb” signs to put on their doors. The signs were replaced with “Room Occupied” signs that notify cast members guests are in the rooms. Guests could still be “disturbed”, though, while in their room. A Disney cast member is required to enter the hotel room at least once a day to ensure guest safety. They empty the trash, if needed, at the same time.
You can still choose to skip mousekeeping. Disney states that “the hotel and its staff reserve the right to enter your room, even when this sign is displayed, for maintenance, safety, security or any other purpose." See the pictures of the sign above. Disney cast members knock and announce their presence before entering.
Some view this as a great inconvenience, but it's not as bad as you think. If you're in the room, be sure the sign is out and you have the manual door guard pushed over so they don't walk in on you by accident if they don't hear you, you're in the shower, etc. You can ask them to come back later, but just remember that they need to get in there no matter what. Bottom line is, it's a different world now and certain security measures are necessary to protect guests and cast members.