This article seems to be mainly circular logic - it doesn't actually answer the question "Why didn't the infant universe collapse into a black hole?" It just says it can't because it didn't. The logic for why it didn't is either missing or opens up other questions.
For instance, the article states
"One, the creation of a black hole relies on not only incredibly high densities but also density differences. To make a black hole, you need a lot of material crammed into a very small volume, with nothing else surrounding it."
So, that immediately brings up the point that "something else" was surrounding the "universe" that was of similar density to its condition when it was created. But, not matter how big you make that "something else", if it has only finite extent, no matter what its total extent, then it should all collapse into a black hole. So, does this explanation require an infinite universe? It is illogical to assume that the "observable" universe is the whole universe.
And the arguments that there must be an "outside" for a black hole to form is just cocktail party quality rhetoric. Even if the "edge" of a mass with density sufficient to be a black hole is the "edge" of the universe, the question still remains "Why doesn't gravitationally compress?"
The answer this article proposes for that question is
"But even if it wasn't a black hole, what prevented the collapse into a singularity? What prevented it is that the early universe wasn't static — it was dynamic. It was evolving. It was changing. And most importantly, it was expanding."
But, that misses the point about why it was expanding. Don't tell us it had to expand because it was so hot and dense, because, for matter to expand through space fast enough to get out of its event horizon is not believed to be possible, according to General Relativity Theory.
So, the "solution" to this problem in the theory is to invent the concept of "inflation" of space itself. That is a phenomenon that we do not understand at all, or even have solid proof that it occurred.
So, this article really has a one-word answer for its title: "Inflation". But it provides nothing in the way of explaining why inflation occurred nor how it occurred.
Like a black hole, this article sucks in readers with its title, but emits no real illumination on the subject.