1) They define "growth" as a stage that goes AFTER raising money. As a founder, growth (planning, executing) should come before you ask for a single dollar (unless you're something like a hardware startup that needs bigger upfront investment). I write about this topic extensively [1] and one of the main differences I found between successful vs. failed founders is whether or not they found viable acquisition channels from the moment they started. Also, in many cases, raising money (too fast) was associated with a bigger chance of failure.
2) They associate a "startup" with getting financing rounds. 0 mentions for bootstrapped founders. Last time I checked [2], a startup is "a company or project undertaken by an entrepreneur to seek, develop, and validate a scalable economic model."
A better title for this article would be would be: "There are only 3 startup stages for funded startups requiring bigger upfront investment".