If your model already understand the distribution of the data (fundamentally this is what statistical models are trying to discover) well enough for generative

If your model already understand the distribution of the data (fundamentally this is what statistical models are trying to discover) well enough for generative models then they probably can do classification well enough. The greater issue is that, for privacy and other reasons, there are many demographics that are not represented at all, or under represented, in medical image datasets.