The realm rejoices as Paradox Interactive announces the launch of Crusader Kings III, the latest entry in the publisher’s grand strategy role-playing game franchise. Advisors may now jockey for positions of influence and adversaries should save their schemes for another day, because on this day Crusader Kings III can be purchased on Steam, the Paradox Store, and other major online retailers.
As I recall its more focused on the three city-states of Athens, Sparta and Syracuse.
Athen/Sparta/Syracuse unique content came with 1.4's Magna Graecia DLC, but Slavicist refers to the Deluxe Version of the base game - its gameplay content are some events, including a chained event around the corpse of Alexander the Great and overall it is considered as a bit "light" for its price (to put it nice). Since the Epirus pro-order DLC was reworked with 1.5 (and those having preordered got the improvements for free), the question stands if some similar rework for the Deluxe-version will happen, too.