So people have (possibly intentionally) tried to cover up the wrongdoings of the past – big deal. Sure beats running the risk of leaving the mistaken impression (particularly on impressionable young minds) that this is somehow a legitimate practice consistent with Halachic-observant Judaism just because some people have done it at some point in the past.
The mistakes of the past must be taught very carefully so as not either legitimize those mistakes, or belittle those who have made them. This is a delicate balance, and I don’t at all blame the publishers of a biography for trying to sidestep such a thorny issue.