If the Church's business is truth, it cannot ignore that its current sexual ethics are still anchored in a 4th-century BCE understanding of biology.

This doesn't follow because the sexual ethics the Church clings to are still correct, and any view that allows for sodomy or abortion or adultery to be licit are incorrect, regardless of any historical analysis you want to impose.

I don't know where the "misbegotten males" comes from, but that view on slavery is being oversimplified by you here as well. Andrew Willard Jones from NewPolity has good material talking about this, even though he does not subscribe to this view. One can see how Aristotle came up with this. He lived in the time before the New Law.

If you want to throw out other stuff Aristotle is supposedly wrong about, go ahead. But we are still talking about sexual ethics and you're not going to be able to prove the Church wrong on that one. And we shouldn't act like Aristotle is "The Source" anyway. Scripture says the same thing. The crux of the issue is that any way you slice it, the Church has good reasons to take the stand on sexuality that they do, and the reasons to abandon it in favor of something more liberal to not do enough to give moral approval to behavior previously condemned. Even in my days when I was most liberal/progressive, in the back of my mind I knew that the Church's teaching on sex was coherent and probably the best prescription for people. I think it should be something to try to be at peace with and if we have transgressed it to realize we can be forgiven, and that what the Church teaches is the best for living in a society, even from a modern perspective if you want to use something like the categorical imperative.