I don't understand your third paragraph. The moment of birth doesn't affect the unborn baby's chances of having someone to talk to, conditioned on survival.

A baby prior to birth hasn't yet started the process of learning how to relate with others. A baby after birth has, and this takes many forms in even the first few hours; including being held, being talked to, being cared for.

Try this thought experiment: how would you design a human whose only goal were to have more kids in the modern world?

What I mean is that our attitudes toward a given act are not necessarily determined by any evolutionary equilibrium. I'm not sure anyway in what sense you think our attitudes toward abortion at some previous times were dictated by an "old" evolutionary equilibrium, and in what sense we'd hate abortion "again".

Try another thought experiment - imagine there existed a plant in our environment, which when ingested reliably caused the termination of pregnancies (or, perhaps, only early pregnancies). On what basis would we predict that, upon involving language and tool use, we wouldn't have learned to take advantage of this plant when doing so served a purpose?