not always, this past Feb we were at SSR studio and late nt is when I checked and the sofa was not made up and there was nothing in the closet either. Had to call and got them the next day.
Now my rule of thumb is to always check the sofa bed first when you get to the room.
I have never had a sofa bed that came made up, at SSR, BWV or OKW. However, have always found the linens in the closet. I think in our two bedroom at SSR they were in some trunk maybe. But in the studio they were definitely in the closet.
Ours has always been made up - but we ALWAYS check when we arrive - the last thing we want is to pull the sofa bed out at 9:00 pm for the first time with sleepy kids and discover someone put it away without getting the bed linens changed - which has been reported to have happened - or need to call housekeeping because there are no linens.
If they aren't there, housekeeping will bring you bed linens and blankets (or may tell you to check the trunk/closet). Note that the pillows are tucked into the frame of the couch as you pull it out on the new beds.
I think I prefer to make it up myself. If you pull open the sofa bed and the linens are on it already, how do you know they aren't just left over from the last guest?