Better question: What 'luxury' hotel doesn't have 24 hour reception and lobby staff?
Heck, I was just as a small 50 room hotel this past weekend that had 3 points of entry, only 1 was in view of the reception desk.
Any of those non-primary entry points would be extremely easy to walk a bed out of without anyone noticing (assuming no one had eyes on the camera at the moment you walked out).