"Underserved" here means that when they see a provider, they are less likely to be taken seriously; not that they are less likely to see a provider.
For example, while men may be more likely to "tough it out" of their own accord, a black woman describing her symptoms is much less likely to be taken seriously.
Are they being taken less seriously when they have serious health issues, statistically? I'd like to see some data on outcomes, life expectancy is the best datapoint I've got and men are clearly disadvantaged there. If women are more likely to seek health care early then it makes sense that more of them don't actually need it, i.e. are "not taken seriously". Maybe there's "collateral damage" but I've also not been taken seriously as a male so I certainly can't agree that it's unique to women and I'll need more than anecdotes to believe that there's a gender discrepancy.
For example, while men may be more likely to "tough it out" of their own accord, a black woman describing her symptoms is much less likely to be taken seriously.