The NPC Dunveri Rodran is missing in Tel Ouada; from the wiki, he's the shipmaster that previously served Bal Oyra and Firewatch. However, that NPC is needed for the Telvanni Mouth quest Books of Faith - he's the guy to talk to about getting rid of the Tribunal Temple books. As a result, the quest cannot be completed.
From the wiki, that very same NPC may also be required for the quest A Tailor in Need; so two quests may actually be affected.
If the intent was to remove the travel route, a fix may be to re-introduce the NPC but to remove his travel options ?