Yes, but not in any way that is relevant to whether Persia is going to be added to the game. There are stray references to "Persia" and "Persian" throughout the Civilopedia, but always in reference to their impact on Civs, buildings, techs, etc. that are in the game. For example, there are the following statements:
1. From Arabia's civ description: "Under Abu Bakr and three able successors, ruling from Medina, the warriors of Islam – fired by the Prophet’s vision – swept across the deserts and plains in all directions, overrunning Persia, Syria, Egypt and much of Anatolia and the North African coast."
2. From Egypt's civ description: "In 525 BC Egypt was captured by Persia, who would control the country until it was taken by Alexander the Great in 332 BC as he systematically dismantled the Persian Empire."
3. From the description of the Market: "Whether called a souk (Arabic), bazaar (Persian), mercado (Spanish) or palengke (Filipino), markets have been around since farmers had surpluses and tradesmen had wares to sell to townsfolk."
4. From the description of the Mercenaries civic: "Xenophon recounts that Cyrus the younger hired “Ten Thousand” Greek mercenaries in 401 BC to seize the throne of Persia, and Macedonia, Carthage and Rome employed “barbarian” mercenaries in their wars."
There's a bunch more, but you get the idea.
