Hotels approval will depend on each individual hotels, some do while others do not
I did a couple of pre-wedding shots before, and i felt that it better to inform the hotel of the shoot. It will save embarrassment for both the photographer and the wedding couple, in case the hotel security/management staff decides to question or stop us
There was one time when the couple decided to shoot at the Raffles Hotel and Fullerton hotel. I sent an email to both hotels informing them of our intention.
Raffles Hotel replied saying that they only allow couples who hold their wedding at the their premise.
Fullerton Hotel on the other hand approved our request. They even sent us a black and white statement for us to print out, in case anyone question us. When we arrived at the hotel, they even gave us a small conference room for us to put our things. We happily used that room for the couple to change their outfits and touch-up their hair and makeup