To my knowledge, room requests are for the room/floor/view/location you are requesting with the Room Tier that you booked. They are not requests for upgrades to a more expensive room.
For example, I have requested “1st Floor” in the past for easier in and out access. I have also made requests in the past like “North side of the property” or “connecting rooms”.
You can always ask politely about an upgrade at check-in, but it’s rare that it happens so don’t go in with any expectations.
If someone else has knowledge otherwise, please chime in.