Prelude: the text:
The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of sex.Act I: you Kant just disenfranchise people.
Congress shall have power to enforce this article by appropriate legislation.
Both fairness and justice demands that any citizen of sound mind and good standing should be eligible to participate in the democratic process. To the modern mind, disenfranchisement is pretty close to a mild form of slavery. Political voice, at least in modern democratic polity, is something of a birthright. The 19th was a hard-won amendment, a ringing victory for women everywhere, not just in the United States, eroding the general legitimacy of patriarchal paternalism the world round.
Act II: franchise and dimensionality
What are the consequences of increased franchise? In a word, indeterminate. In game theory, we've got this result called (of all things) the Folk Theorem. The skinny on the Folk Theorem is that in repeated play, all bets are off and any equilibrium result can be sustained. So, with only white landowning males able to vote, you can wind up with a heavyhanded tyranny just as you can wind up with a sharply constrained market-preserving federal system. Ditto for universal franchise. What ends up important is the median voter.
How does adding women to the mix change the position of the median voter? That's a thorny empirical question. It's important, but close to impossible to know the direction of the arrow of causality leading between ideas and policies here. Could a rising tide of dignity for everyone have both pushed for the 19th and for the civil rights revolution that followed? In other words, to pick out the specific (consequential!) effect that women's suffrage had on the scope and scale of the state, you'd need to isolate the correct counterfactual. That is, to be generous, challenging.
And in light of this analytical challenge, I can't really say whether or not universal franchise is meta-euvoluntary or not. There are still piles upon piles of gender-specific legislation that deals with trades on the margins of euvoluntarity like access to birth control (and I mean for-real access, not just subsidies), sex education, abortion, prostitution, pornography, adoption, marriage, & lots of al. If it's the case that women help draft exchanges like these into the realm of the euvoluntary by way of direct participation, then there we go.
Of course, the nettle of the Folk Theorem still stings both ways: the counterfactual median voter could still cut ice in favor of greater restrictions on trade. I don't pretend to know what the alternative actually is. Beware folks who claim they do.
Is the 19th meta-EE? Indeterminate. Is it still normatively good? Unless you're some kind of misogynist, then yes, of course.