Awhile back there was a rumor that there is some kind of MacGuffin the characters will be after, and I speculated that it could be the Journal of the Whills, and maybe we would learn something about them or the Force indirectly through that. It would be a nice way to tie that original idea into the last Saga film, while not being too out there for general audiences.
Since this is the last film of the Saga, they probably will touch on the Force a little more in some way, or illustrate what Balance is exactly.
It would be cool to learn more about the Whills and such, but I can understand their hesitation to approach that subject, because audiences, and especially fans, were really critical of the midichlorians as a concept back in the day (and it still is something a lot of people choose to forget). I don’t think people want the Force overly demystified, and honestly neither do I. I think how the Force works should be left up to interpretation to a certain extent, and the more you explain it the less flexible it becomes.
I compare it to Taoism a lot. The first chapter of the Tao Te Ching basically says, “The Tao that can be named is not truly the Tao.” Basically, trying to understand or quantify the Way universe works is essentially a fruitless effort, and you really have to surrender yourself to it in order to be in-step with the Universe, if that makes sense. It’s like faith, and that comes back around to how George originally meant for the Force to be a meta-religion that can stand in for any religious faith or belief system.
It would be cool for them to explore the Whills more in some other form of media, but maybe it was the right call to not overexplain it in the Saga films. For me, I would just like for them to possibly address this apparent cycle of Darkness and light that exists in the universe, and how Force ghost Luke, Rey and potentially Ben Solo will play a part in dealing with it. Which I think is subtle enough for audiences to understand and apply it to real-world issues in their own lives.