Arcadia just has shower curtains.
As Moley said some time ago, the bathrooms are modular units, and as such are intended to last the life of the ship. To all intents and purposes the bathrooms cannot be changed. You might be able to change the grouting, and put in a shower door, but the loo, basin and sink have to stay.
The bathrooms on Arcadia are really very tired, and there is no easy or economic fix.