Maybe you haven't been following this story closely but it's not about allegations from 20 years ago, the only reason it's mentioned in the documentary is because it's apart of R. Kelly's story and helps flesh out who he is as a person.
Before this documentary was made, the parents of the women who live with him have been exhausting all of their resources to bring R. Kelly to justice for things related to their daughter. They've been on MTV and other media outlets long before this documentary was a thing. The documentary is yet another platform for victims of alleged crimes that have taken place RECENTLY. The narrative that there's some secret white men behind the scenes trying to paint Black men as the face of the MeToo movement is bullshyt and doesn't pass the smell test.
At one point people were pointing at Harvey Weinstein and Kevin Spacey claiming that nothing has happened to them when in reality, the impact to both of their careers and livelihoods has been more damaging than R. Kelly's who still has a career. Kevin Spacey was in court less than two weeks ago for his crimes and Harvey Weinstein is out on a 1million dollar bail for his crimes, there's also a documentary on his crimes that premiered at Sundance.
Point is, this is about R. Kelly not Black men.