Unfortunately, I don't think it has been improved much, at least not in the way you probably care about. The updates to the game have been mostly about adding stuff, not fixing or improving what is already there. If anything, the new content makes the AI weaker, as there are now more things it can't handle well. Of course, there's always a chance you will like some of the new things. For me, the main thing I got from NFP was the Maya, which is probably my favorite civ in the game.
If you want a Civ game with decent AI, Civ 5 with Vox Populi is probably the best option. It is far from unbeatable, but vastly superior to Civ 6. The most obvious difference is how much better it is at war, but the AI is more present in every arena of the game.