Others have speculated that we may get a different new region in lieu of the City. I sm now mre convinced of this. One hint comes from The Highlands rules:
Surrounding the land of Talisman are four great kingdoms known as Regions .
I'm not sure the city would count as a "great kingdom", nor would a blow up map count as surrounding the land.
My second hint came from the upcoming Sacred Pool expansion which features a Stable deck. It occurred to me that this was the sort of thing I'd expect in a City expansion. Then it occurred to me that if FFG d oesn't make a city board, they might want to seed the small expansions with optional optional rules for spending money in the City.
While the Stable deck doesn't rule out a City expansion, it it consistent with omitting the city from the expansion base.
Thoughts?