King Jorunn's dialogue there is set up for a player who then goes on to meet Vanus Galerion at the Mages Guild and complete Messages Across Tamriel to kick off the invasion of Coldharbour, but you've already done that, so it doesn't apply to you.

Killing Sinmur should be the end of Cadwell's Almanac for EP, so you should have got an update to that quest to return to Cadwell. Perhaps you missed a quest somewhere along the line? Are there any Objectives in the Cadwell's Almanac checklist that are incomplete? If Trolhetta is incomplete, you likely missed the side-quest Worm Cult Summoner, given by Plays-With-Fire at the bottom end of the exterior section between Trolhetta Cave and Trolhetta Summit.

In your Journal, you should have a tab next to Quests labelled as Cadwell's Almanac, with this icon:

It only lists the location objectives, not the quests that are part of them (which you can see here), but ones that are complete are checked off.