I've read through several legal sites and it appears that they all agree that YES, you can expect privacy .....
"As a general proposition, a person who rents a hotel/motel room has the same expectation or privacy as a homeowner has in their own home. This remains true while the room is currently rented."
Others have added that this is as long as the room is paid for and guest not engaging in illegal activity.
But hotels have loop holes .... so in Disney's instance they can "claim" it is for cleaning and maintenance.
"Generally, yes, you have a right to expect privacy in your hotel room as long as you are using the hotel room in a normal, responsible way. However, if you are engaging in anything illegal or disturbing other guests, hotel management can enter your room without your permission.
Note that hotel management, not the police, can enter the room without your permission and hotel management cannot give the police permission to search your room. The police must go through the usual process, which usually means getting a warrant before they are allowed to search your room.
A final exception to your right to privacy is for cleaning and maintenance. Hotel management does have the right to enter your room to clean or perform necessary maintenance."
PERSONALLY, my biggest issue is that they are entering rooms that are occupied - uninvited; and even with my sign up and lock on, they will knock and ask to enter. I don't allow strangers to enter my room while I am there that I didn't call to come address an issue.