That probably won't happen. The families that have children will die out, and the next generation will be almost exclusively have parents that chose to have chi

That probably won't happen. The families that have children will die out, and the next generation will be almost exclusively have parents that chose to have children even when cultural norms were turning against it. That'll probably lead to a rebound in fertility, which funnily enough we're already seeing - the lowest it's been was 1.26 in 2005 and since then it's gone up a bit. But we'll need to give it another few decades first.