My 2cents, I don't stay at Hyatt, all my stays are at Marriott Bonvoy, LOL. But for me I get a automatic checkout bill at the end of my stay, never need to go to the front desk/nor anything. I usually opt out of any room service ( get 500 points a night for this ). As a general practice hang the no service and do not disturb for the appearance someone is in the room. I've heard another tip for making sure no one enters is to turn on the radio or TV so people at the door hear the sound. I can't confirm the effectiveness of such to prevent entrance. As far as I can tell no body comes in and replaces anything, empties trash etc...
If I was to never have even slept there, I doubt they'd know. I thought I read somewhere someone died in the room and nobody discovered till they came to clean the room at the end of their reservation stay.
