Your antinatalistic conclusion is only sensible if you presuppose the most extreme form of negative utilitarianism, and grant the elimination of suffering lexical priority — though you would still have to justify the notion that pro-mortalism is the natural extension of such logic, since species-wide suicide could potentially cause great levels of suffering in and of itself. There is no logic explained behind how we can meaningfully measure suffering, let alone aggregate it across the phenomenological experiences of persons on Earth.
Not to mention you would still have to justify the lexical priority of the negation of suffering, which is highly dubious, since suffering itself requires some criteria; what is suffering? Is there a meaningful difference between suffering with purpose, and suffering meaninglessly? I, for one, would choose to exist even if I knew how miserable my life was going to be, because I do find qualia to be meaningfully valuable. Of course, life may be utterly wretched for us, but it does not necessitate that great suffering will continue to persist for all generations to come, as long as humanity prevails and marches down the path toward human flourishing.
Antinatalism is the epitome of the female mindset, since it is contradictory, selfish, and subverts civilization itself; furthermore, it is impractical, since it could never be properly applied without betraying its own values. Would a theoretical button that eliminates the concept of life be one we ought to press? Perhaps, since it would be a hypothetical scenario inside a vacuum without any unforeseeable consequences, but that is all that can be rationally granted in favor of such a philosophy.
Even the post you cited includes many problematic holes, since most of the arguments made cannot properly address the non-identity problem; even if one were to try to appeal to general suffering that does not require a specific subject, it would not escape this issue, as you are appealing to the consent of a non-existent being; the potentiality of individual consent, which cannot be coherent without an individual. I have seen some antinatalistic philosophers argue that no life is worth starting, but it seemingly fails to solve the issue, since it discusses a subject (life) without a subject — and it leads to repugnant conclusions about people who are already alive, though you seem to have no issue with that. I do believe some of the counterintuitive conclusions that the non-identity problem leads to can be addressed, but the optimal way to do so is with impersonal ethics; consent cannot be coherent within impersonal ethics. I suppose you could appeal to the notion that any life being brought to existence necessitates suffering, but the problem is that any level of suffering alone does not immediately justify nonexistence. It would certainly be immoral to conceive a child in extremely bad circumstances, in which basic necessities cannot be met, but as long as the person's needs are met — a meaningful life could be lived.
Ironically, this entire philosophy is antithetical to NU in the public space, since antinatalism is strongly correlated with existential nihilism — I would even say it necessitates it, in a sense. People who are nihilistic are more likely to be depressed, lead meaningless lives, and generally suffer more because of their bleak worldview; the irony is that the framework which preaches the elimination of suffering causes greater suffering to already present moral agents.
An anti-natalist is only able to make this argument because existence allows him to. In making this argument, it is ironic that he turns against the very thing that made it possible in the first place for him to make this argument. In general, life is fundamentally what allows such arguments and the meaningful discussion about the "purpose of life" possible — hence every antinatalistic argument suffers from a sort of supervenience. It is then suspicious to apply the attributes of meaning, purpose pleasure and pain to life itself. Life stands above these human ideas which should apply only to entities within life. If I remember correctly, while in a different context, Wittgenstein has made a similar argument about language itself: it cannot be coherently used when you strip it of its natural purpose, thus he argued many philosophical quandaries were merely language games, such as: "This sentence is false." One could consider the antinatalistic usage of nonexistence as a coherent concept to compare against as a language game in and of itself, especially the asymmetry argument.
