I imagine the situation in Gwaren may end up like Amaranthine for the Warden in the aftermath of Howe's death. Vassals who hated him and vassals who loved him, power struggles, political bs, and the new ruler has a huge mess on their hands.
I do wish the political scene in the nations of Thedas was given more in-depth attention, because what would basically happen is that no matter what the teynir of Gwaren passes to the crown, as Loghain is either dead or a Warden and Anora is either deposed -- which is basically another word for dead, realistically speaking -- or the Queen of Ferelden.
As it stands, it would pass to another family down the line, but I imagine that it is like Amaranthine to a degree. Loghain wasn't just a teyrn, he was a symbol. He represented the ideals of Ferelden, where hard work and loyalty paved the way for his ascent to a high nobleman's rank. He was as much representative of Ferelden as a Mabari was.
It's bound to exist that no matter how well-loved the replacement may have been from wherever they were, they're going to face resentment and scorn because they're not Loghain. The common folk may feel that with Loghain, it gave them hope. He was one of them. The nobility also probably enjoyed him because he fought for them. He was good to them. So power struggles would exist.
But a blue blood? Someone like my male Cousland in my "10 Wardens in the same universe" headcanon? Despite how loved the Couslands were, there's got to be some sort of rebellion going on that would need to be addressed. More so if it's an Elf in the role, as racism would still be rampant.