So I started my first healer and as I was running through the main quest with him, I got a request to meet with Abnur Tharn and start the quest which I believe leads to the Elsweyr storyline. I was barely 15th level, had not had any interactions with Tharn at that point, and suddenly an Imperial Battlemage of the Elder Council who at that time is still locked away in Coldharbour sorting sole gems, wants to talk to me, to stop the three banners war.
In this case, the timing was just right to start the portion of the main quest where I got to meet and free Tarn, but still that was a huge jolt when it comes to immersion.