Mandalay Bay knew exactly who was in that room within one minute of the shots being fired. That information was immediately relayed to the Las Vegas Metro Police.
You have info that hotel management knew within one minute (that's a mere 60 seconds, for those of you in Rio Linda) WHAT room the shooting was coming from? If they had that figured out, then yes, they should know who had booked that particular room. Who would actually, physically be in any booked room could be another matter...
You have a supporting link for that, or as usual for you, you're talking out your stern-tube vent?