Unfortunately, Rise and Fall doesn't appear to improve the AI inconsistencies present in vanilla Civ VI. Some AI-controlled civs still act almost randomly--Japan declared war on me twice in one game despite never sending its military my way--while others are a bit more clever, declaring preemptive wars or offering strategic trades at opportune times. And while the Loyalty and Governors systems enhance city management and encourage you to pursue a wider variety of specialties than just your intended victory condition, religion remains the least dynamic of the avenues without anything in Rise and Fall drastically changing it.
As Civ VI's first expansion, though, Rise and Fall works so well with the base game that lingering issues are minor. It enhances, rather than overcomplicates, systems that were already deep and layered to begin with, while introducing features that keep each game engaging from start to finish. Ages in particular provide room for struggling civs to climb the ranks in the late game and keep leading civs on their toes, and the Governor and Loyalty systems add to the city-specific strategies that helped make the base game great.
