I purge, you purge, they purge, we purge, you all purge... Serpentspine summary.
-Anonymous
All dwarves have at least one narrative about wiping out orcs or goblins, if not their main narrative. I know "I'm not forced to purge," but I'm supposed to, mainly because of the quests that explicitly state it, so much so that it becomes background noise and you don't even notice.
I completely understand the remnants, since there's absolutely nothing you can do but start the process almost from the third expansion of quests. Even though everything is pacified in 1444, those who personally suffered through it all for at least a century or two will still remember it with great emotion.
But with the adventurers, I think they have almost no excuse. It seems they absorb the hatred of the dead, and not just their culture. Ironically, the slave-owning dwarves could end up saving several races from extermination on the Serpentspine. In the best-case scenario, they might end up reforming and assimilating the other races, more or less like the Imperial dwarves do with the orcs, but more likely, they'll face a revolt from 99.99% of their population.
Orcs are basically monsters. Personally, I think they're the wild card in Serpentspine, since the dwarves already have the "we were promised Serpentspine 10,000 years ago" storyline, and the goblins are finally going to become the stereotypical goblin nation (AllClans, what a great nation you are... It's a shame you end up erasing everything the goblin nations once represented). So, we're left with the orcs... At least the established orcs can be considered normal nations... And one of these isn't canon anymore, so we'll just have to see how they handle it. At least the religious fanatic trope is already taken.
As for the rest of the orcs in Serpentspine, I basically hope they use them to terrorize Anbennar or that they dedicate themselves to wiping everyone and everything out. I don't think they'll use them to create nations in the traditional sense.
Finally, the goblins are out there doing their thing, like dying. I partly understand why they're involved in this; it's literally the only way they know how. They hate the orcs for having enslaved them in recent times and the dwarves for being their eternal enemies, but they seem more relaxed about purging everything.
And the kobolds... Their chieftain died, along with any possibility of having a dragon leading a kobold nation and wanting to be that leader (Balris is more of a spiritual guide now that his children survived against all odds). At least they tolerated humans, as far as I know... Unfortunately, that nation has always been cursed, and we may not see them again for a very long time.