Yes, a lot of what you list is going to be done. They do change out linen, bedding, carpet, etc of the wear and tear variety.
The primary reason it goes in is twofold.
One, to get the hull completely out of the water so they can inspect and recoat it. I am sure you have seen them painting the upper parts of the ship at some point, well, this is where the lower gets done.
Two, inspect and update all safety/emergency equipment as needed.
They also take advantage of this downtime for any renovations, remodeling, etc...