What is the purpose of this cage on the wall of hotel room?

I am not sure about Morocco but this is your run of the mill newspaper rack. If you were in a breakfast restaurant in the 60-80s you would likely see this with a different section of the newspaper separated and hung. These were even at the big double arches. People may put magazines on them but it was made for newspapers.

It would be normal for a restaurant to get 3 major newspapers and see 15-20 sections strung out all over on this.

Note: Based on the comments around the lock. Locks were normal and the newspapers were dropped in the middle rolled up. I don't think the lock was meant to protect the newspapers per se because it is just a flimsy cage with huge holes. I think the locks were there to convey that what is inside should be paid for. If I remember right most places left these open with a "pay jar" adjacent. Some places only provided one newspaper to read and often people that paid left portions of their on the rack after.

I have also heard others comment about this being used to cover a thermostat control. I have stayed at a lot of hotels and I have never seen one that you could bypass with a long straight coat hanger. I think that use is debunked.

Old fashioned wall mounted drying rack

Usually wooden devices like this on walls open up and hinge down, and are old fashioned drying racks.

Here is one with arms that open, and is not a lean out rack like the one in your room.

Clothes Drying Rack - Old Fashion Design Copy

It bothered me to see the wife having to work so hard to set up a collapsible drying rack to dry her's and the kids swim stuff so I started researching a wall mount setup that would fold flat against the wall. Most designs I found were large lean out designs but I needed something with ends sticking out to hold swim caps open to dry. I came across one old antique design that was just what I needed so I took the idea and updated it to my situation. This was a one day construction and then a couple of days of polyurethane stain coats and I was in business.

Link for photo

Back to your device

Now, you can even see at the bottom of your device that it does unhinge and open up, due to the shape of the wood, and you can see the white mark on the wood where the rack collides with the rest of the structure.

Just to be 100% sure

Just to be 100% sure you could simply email the hotel with the photo and ask them, then let us know which answer was correct.