Would you like to elaborate on that a little bit further? I mean I do believe you are a little bit more logical then what that sentence seems to project, so maybe I'm misunderstanding something. What I will say is that probably all BH's are born with spin [Kerr metric] for obvious reasons, and that spin along with any charge, is negated over time. The amount of time is the essence here, as imo to negate all spin, would take a heck of a long time. So in essence most BH's would be Kerr metric, Kerr-Newman, or Reissner-Nordstrom. Is this what you are referring to?