I haven't played Revenant wings so I don't know how it ends...

Then you have some sort of cataclysm and the the rise of St Ajora and those silly warriors..I have forgotten their names and the events in FF Tactics and Vagrant Story:

Final Fantasy Tactics - Wikipedia, the free encyclopedia

From that we know Delita becomes King after he kills Ovelia.
A definitely untrustworthy fellow..

So you're right. That's pretty much where the Ivalice series ends unless Square someday chooses to do another sequel.

With Matsuno gone that seems highly unlikely.

So things do appear to ultimately end badly for the people of Ivalice.