Light Ending Spoilers for Avowed.
I could very easily imagine a sequel to Avowed set in Aedyr even following the same main character of Avowed, I'd like that and I can already picture the scenarios which calls the Envoy back to Aedyr. Not really sure what the main story would focus on, but there's a logical setup for recalling the Envoy back to Aedyr, perhaps it could be focused on the fall of the Aedyr Empire.
To my knowledge, the main character in Pillars is the same across both.