Its something I keep coming back to and was reminded off in part because of speculation of who we'll see based on city states currently in the game, a tried and true method of wink-wink-nudge-nudge'ing us about what we can expect to see. What I'd hope to see at some point, if not with this expansion pass in Civ 7 perhaps, is cities that are both in the city state pool and the foundable cities pool for their respective civs (and perhaps sometimes in multiple civs lists!)

Basically imagine if London could, assuming England isnt rolled in the list of main civs being played either by you or the AI, appear as a commercial city state. Other possibilities include everything from specific German or Greek or Mesopotamian city states that are farther down the spawn list for their respective civ also having a version that if spawned as a city state wont be default found-able. There's a lot of cool interesting ones that could occupy this position in terms of their abilities and it'd be cool to hear other's ideas as such, but it'd also add neat flavor as well especially in consideration of some civs abilities and focus's. Its a bit of a disconnect sometimes when Pericles' focus on suzerainty of city states, reflecting the Athenian League etc, is being used with cities that were never Greek as it were, but if if you're scouting as him and find Sparta or Miletus as city states that you can choose between forcing into your empire or diplomatically allying with. A historically German city state being absorbed while you're playing as Germany by an aggresive France or such could provide fun roleplay justification for you to declare war in one game, or just exist normally among-st your cities in a different game. I could go on.