I don't think there is an agenda.
At any rate, what I wanted to say, and I can't read the article, beyond a few lines, is that birth rates are already dropping in many places, and "developing" countries are also showing that they are on target for the same thing happening as happened in richer countries, but at a faster rate than previously happened with richer countries as when they started having lower birth rates below replacement.
I also did see that the article said that that it will at least be a few decades before population collapse poses a problem.
Since I can't read beyond that, I'm wondering if they are taking the world as a whole, because even before populations "collapse", it will still look like the same number of people, but the problem in richer countries is that it's an inverted pyramid with aging populations at the top composing the largest number of people.