Millenium City is a good time to explore/contrast not only established relationships and take strides towards resolving ones with unfinished business, but also a good time for what ifs, relationships that might have been, or ones that you can see unfolding in the late stages of the game.
In the comments, tap people you'd like to thread with, with an idea for foundation if possible.
Also, a proposal: Reconsidering the ranking system so that it isn't so heavily weighted towards high and low ranks indicating like or dislike, respectively. Looking at my own links I'm finding there should be some in-between space for rivalry or other connections, because that can be just as significant.