SPOILER WARNING FOR BOTH THE MAIN QUEST AND SIDE-QUESTS IN ELSWEYR
I noticed after I completed the last quest for the main story in Elsweyr, there were a bunch of NPCs from the various side quests in the region (Ashur, Razum-Dar, Vastarie, Mizzik, etc.) alongside the main quest NPCs (Gharesh-ri, Zamarak, etc.) that you could talk to, similar to the Alinor palace in Summerset. Unlike in Summerset though, the side quest NPCs vanish if you leave the area/zone and if you go back to the palace, only the main NPCs are there. I don't know if this is a bug/issue or how things are set up, but it'd be really nice if Rimmen's palace functioned the same way as Alinor's in this regard where you can go back anytime to re-explore dialogue with the NPCs.
Luckily for myself, I took screenshots of most if not all of the NPC dialogue that I saw. But as it stands, I believe if someone doesn't do all of the side quests in Northern Elsweyr before finishing the main quest and leaves to go do them in the hopes of seeing certain NPCs in the throne room, the NPCs will not appear even after doing them.