After Sin is defeated and falls you see Gagazet and other areas. And a major plot of X-2 was the Guado massacre of the Ronso and their decision to take revenge or not. There is no such thing on Revenant Wings.

And yes, the game made it perfectly clear that Ashe's sole concern was her dead husband. Although in two of the best lines in the game she shows a bit more depth:
In all of Dalmasca long years of history it has never used the Dawn Shard, this is the Dalmasca I want to preserve
and
The Rassler I knew would not want revenge
I think the problem goes back to the fact the main writer had to leave mid stream. The Bur Omisace plot was left too open, after the story going into pains to show how much misery they received for aiding the team it felt very unfair / amoral. If I was writing it I would have made Bergan just get Larsa and go meet the team at Miriam. There was no need to attack the refugee camp.