Even if it isn't a legal requirement, I would hope it would be "minimum standards" requirement of all the major chains. I suggest you contact Hyatt.
It had the Perspex thing on back of the door that it should of been in but it was empty.
I might just contact them because you just never know if someone is in a situation that they need to know how to get out. I was at one end of the hotel and it was like a rabbit warren down there with a few ways to get to the lifts.