I'm just for giving it the benefit of the doubt. I don't think Lucas set out to nail things about the Force down with this further detail, merely add more food for thought. Like all of the great mysteries of life, such as how life got started in the first place, it's something that we can't really pin down and prove.
I think it makes sense that in a society like the Old Republic, they would be aware of things like Midichlorians in the same way we here on Earth are aware of Mitochondria. They happened to notice that most Force users tended to have a higher midicount, and the practice of using midi-counts to pre-screen near infant Jedi Hopefuls is born. To me this makes plenty of sense, and doesn't change anything about how the Force was in the classic trilogy. It's really just our perception of it that has changed due to getting more peices of the puzzle.
People here on Earth theorize that Mitochondria is the source of all complex life. Some people think that makes them "god". Obviously none of it can be "proven" there's just theories and counter theories held by different people.
I think if we take just what is given to us in the films, we can figure out what we think the "real deal" is, and I think that's what Lucas intends. He said once that answering the mysteries of life isn't as important as questioning them.