This article is answering a different question to what it is asking. It's asking "What is the most effective strategy to freeze your eggs if you're absolutely certain you will need to".

The reason women freeze their eggs in their early 30s is because they still have a good chance for it to be effective and they now have a strong idea they'll need to. You don't have that second piece of information at age 19.

Or to be specific: What is the size of the cohort of women you are expecting to freeze their eggs at the age of 19, who will use those frozen eggs. How many of them will give birth to children without the help of IVF, and how many will choose never to have children.

I think this article is a good example of rationalism. Which is basically getting very mathsy about 1 specific very of the data, without viewing the data in the context of the decision that is being made.

For example, what is the percentage of women you expect to freeze their eggs at age 19, who you then expect to be unable to afford the $500 every year to keep those eggs frozen over the next decade?