For the entire series, Kaladin will try to tempt Shallan to cheat on Adolin. Then he'll give up for no reason, go home to Hearthstone to help sick people, and do absolutely nothing in the last book.
Adolin will be upset because Shallan won't get mad at him.
Jasnah, after telling Shallan what her powers are in the first book but without teaching her how to use them, will now disappear for most of the series. She'll come back near the end, but it will turn out that she now has nothing else to teach Shallan, and she'll just have to figure it out for herself.
Pattern will die, but he will still exist in Shadesmar. He will teach Shallan how to use Shadesmar, but will then be killed again, except for real this time.