Personally I feel like the game is pretty complete. A patch would be great, but I can hardly imagine adding too much more to the game.
For me, this game is so good as it is that I'm not even thinking about DLC or even Civ 6 for that matter. It's hard to comprehend the game getting better than it already is.
You have clearly avoided the multiplayer section
I think the only issues I can think of is the lack of multiplayer optimization, lack of mod support in hotseat and multiplayer games in general and the severity of the Warmonger penalty, I mean, on Warlord I'm afraid to attack a frigging city state because of how hated you become straight away, and there isv ery FEW opportunities to reduce it.
I could imagine at least half a dozen of additional mechanisms as big as works of art. All the same, I really doubt anything is coming.Personally I feel like the game is pretty complete. A patch would be great, but I can hardly imagine adding too much more to the game.
A patch is absolutely neccessary. Early game wars need to be less punishing, culture building should give more culture, Piety needs to be made a viable/logical option for any difficulty.