Honestly, with the coming of the Byzantines (395-1452), and considering that the campaign considers that the Abbasids also cover the period before the Crusaders and the Mongol invasion (750-1259), civilizations like the Persians are likely to appear. The myth that civs could not be from ages earlier to the year 1000 A.D seems to have been banisheed into thin air.
The Persian could exist considering several of their dynasties: Saffavidas (224-651), Saffarid Dynasty (861-1003), Samanids (819-999), Buyid (934–1062), Khwarazmian Empire (1077–1231). Jalayirid Sultanate (1335–1432), Qara Qoyunlu (1374–1468), Aq Qoyunlu (1378–1503) and also the Safavid for Post-Imperial (1501–1736).
In fact, there is already a Persian model based on it on the forum (The Persians civ concept (Second version)). Let’s see if next year with more luck, or some survey they consider the Persians, and maybe the Timurids: