As I understand it, the grandparent's argument is that earlier on in history, wars (and violence in general) would cause a reduction in the percentage of males. For example[0], in Soviet Russia following WW2, the ratio of young men/women dropped to 0.7. And that given that the China and India are more peaceful now (for various reasons), this violent force does not come into effect.

I don't understand how your response is relevant to the above argument.

[0] https://www.ucis.pitt.edu/nceeer/2007_820-4g_Brainerd1.pdf

Peaceful countries with balanced population has better woman rights. What China/India has, isn’t really natural because they tend to abort female babies.

That's not too far off from the figures quoted in the article – a 2% difference of 1.4 billion (China's population) would be 28 million, which is not too much less than the 34 million difference quoted in the article.