While there are advancements in robotics and artificial intelligence, the notion of robot butlers is still largely conceptual. The potential implementation of robot butlers in Miami or any other city depends on various factors, including technological feasibility, cost-effectiveness, and societal acceptance.

Given the current state of technology, it is possible to develop robots capable of performing basic tasks such as delivering room service items, but the scalability, efficiency, and safety of such a system would need to be thoroughly evaluated.

Moreover, the introduction of robot butlers would have implications for the hospitality industry, particularly regarding job displacement concerns among hotel staff. Ethical considerations and public acceptance of robots interacting with guests would also need to be addressed.

At present, the widespread use of robot butlers in Miami or other cities remains speculative and will likely depend on advancements in technology and society's readiness for such innovations.