I apologize for this confusion. I've updated the section with the inaccurate statement @Richard Y Chappell quoted.
Thank you for bringing up other important considerations and limitations of these studies. You are right that, with this post, I don't intend to make any claims about the extent to which anyone should let productivity effects determine their decision whether or not to have children. I'm just hoping to help better inform those who factor it into their choice (although, again, you make a good point about these studies' failure to account for the counterfactual of people who want children deciding against it).
Unfortunately, I'm learning the article may be a bit misleading. I'd see some of the other comments for more details.
Thank you so much! I'm very happy to hear it was helpful for you.