We explore the **evolution of marketing** from AI-assisted to **AI-autonomous functions**, highlighting the profound implications for Chief Marketing Officers (CMOs). We argue that while AI currently boosts efficiency in tactical tasks, the future involves **specialized AI agents** operating with a high degree of autonomy, necessitating a shift in the CMO's role to that of a **systems architect and ethical steward**. We argue the crucial role of **multi-objective reward models** in guiding AI behavior and managing **inherent systemic risks** like algorithmic bias and "reward hacking." Ultimately, we outline a **phased roadmap** for organizations to transition to this advanced, AI-driven marketing ecosystem, stressing the importance of **human oversight and ethical governance**.