To me balance in the force mans light and dark sides together. The concept of the force being out of balance seems to originate with TPM and the PT doesn’t really give enough for it to feel balanced after ROTJ. At that point all the good and bad of old have been wiped away and there is just Luke. But to really finish off the story as it was expanded in the PT, we really needed to see how it gets balanced and the current story seems to be headed that way. TLJ was filled with it and so was TFA. So even if the title of the episode isn’t Balance of the Force, I expect that to be a one line summary of the story.
One thing, don’t mean to come off rude, but the light side and dark side of the force do not equal balance. The dark side is a corruption that will always create imbalance. Balance is recognizing the dark side within all things, and accepting it’s existence, in order to fulfill self satisfaction, because there is no way anything can be ultimately good in nature. It’s not the same as actively using the light and dark side of the force. Yoda finds inner peace and enlightenment in The Clone Wars when he battles his inner demons to find acceptance (his final arch in Season 6). To morph the message into “the dark and light side of the force together is true balance” is like saying “kids, it’s okay to do drugs half of your time, because that’s the proper way of living.” (Because Star Wars is a story of children).