There is no lack of contemporaneous information/live footage/etc., when it comes to Queen.
And so, I wish this movie told us something that we did not already know.
As for me, what I would like to know is how these seemingly very different people (May, Rogers, Deacon, Mary, Jim, FM's parents) ended up being so loyal to FM. I.e. These people respected the privacy of FM even when it seemed he didn't care about his privacy - the tabloids. These people respected his privacy despite the fact that he left them behind while he took center stage.
Any one of them could have written a tell all book - but they didn't.
The movie portrays FM as being very self-centered. But there must have been more, at least to me, or else he would not have had the loyalty that was given to him without question.