Would moving a dwarf's bedroom give it an unhappy thought?
I'd assume not having a place to sleep would give it one. What about if there was a new room already made? I have seen dwarves become attached to weapons... can they become attached to furniture?
Solution 1:
Dwarves are fickle enough as is, sometimes ignoring assigned rooms to sleep in the hospital, or barracks. Dwarves do not get attached to furniture.
One important bedroom-related function is jealousy -- nobles get jealous if they perceive a "lesser" dwarf having better holdings than their own.