Yeah, Rian’s doc was pretty transparent when it came to Rian and Mark’s disagreements. JJ’s doc does feel a lot more censored in that way.
Another thing I would worry about in a fan-made “exposé”, would be the writer’s own bias. Even now, a lot of interviews and information are being used by certain detractors as being evidence of “Disney/Lucasfilm’s SJW agenda”. So I could easily see a hypothetical book being used as way to frame “Disney” Star Wars in the most negative way possible.