It was expressly not to be tabloid journalism, though almost everything about Michael Jackson somehow becomes, because attention = ¢€$#.
To me a serious journalist finds out more interesting questions than what the public has been trained to have on their minds. Anyone could have put those questions to MJ, and everyone did, Winfrey, Sawyer...
A good journalist has the ability to make the interviewee open up. Michael didn't need even that, he was so eager to be humanized that he tolerated Bashir, who was totally superfluous and detracts from understanding MJ. Probably Bashir's team has hundreds of hours more footage with Michael, showing him to be a human being and also more magic stuff we might never get to see unless it becomes really popular to show Michael in a good light.
I think the best movies yet to understand Michael are the candid footage mainly filmed by his own team like The footage you were never meant to see & Michael Jackson: Commemorated.