I don't think it's unusual at all, my grandson, opts to sleep with his father in our guest bedroom when they all come here, in spite of setting up a bedroom each for both grandchildren they bed hop between the three bedrooms we allocate for them. Only we in the 4th bedroom remain undisturbed!
My husband established "own rooms" with ours from the outset, unless they were ill or there was thunder and lightning, I let him get on with it, he'd been down the parenthood road with his first family, I knew nothing! It worked for us they went of like lights, sometimes when we were out late with them at friends or relations, we got them into their pyjamas before we got in the car and somehow got them up to bed when we got home without them waking up!