There's pretty good evidence that Roe V Wade was responsible for a drop in crimes in the 90's, as fewer births in the 70's meant that fewer unwanted male children grew into criminals in their 20's.
I can see some limited pro-natalist arguments, but I'm mostly on the skeptical side. "MOAR KIDS" seems to be one of these simplistic "Elon ideas" that people just accept unquestioningly.
Human beings aren't plants to grow in a field, requiring nothing more than water and sunlight. To make a successful, productive human being in the 21st century requires a *lot* of effort. I suspect that Twitter pro-natalists, (Elon included), expect that the bulk of that work will be performed by their wives / baby mammas.