There are dozens of writing mentors/gurus, and every one of them has discovered the story structure, or the 3/7/10/50 basic plots. All of them are different. From vague and meaningless "beginning-middle-end but not always in the same order" to Blake Snyder's Beat Sheet or Dan Harmon's story circle(Campbell's hero's journey).
They all are kinda true, for the same reason you can find the proof of UFO in the Bible, or determine that there are "two kinds of people", or discover 4 personality types. Anything can be shoehorned into any kind of pattern if your definition is vague enough and you're willing to stretch the meaning of things hard enough.
Different writers are familiar with different structures and use ones they prefer, bending and modifying them as they wish. Some writers break the rules on purpose. Some writers get high out of their minds and write stream of consciousness novels in a weekend. Any of that can result in a great/famous/successful story. Finding the pattern that fits all of that is only possible if it's so vague that it can fit literally anything, at which point it becomes meaningless.
Plots and story structures can be picked up and used when it's convenient, it's easier to write when you have a paint-by-numbers structure to hang your story upon, but there isn't the one story structure or the six story types, that's silly.
You misunderstood the research in the article. They aren't saying that there are only 6 plots, rather that there are 6 basic progressions of valence (i.e. mood of the story) that almost all stories are minor variations of. There are of course variations that are outliers, and the way in which these valence transitions occur differs from story to story, but the emotional "ride" these progressions create should be very similar.
They all are kinda true, for the same reason you can find the proof of UFO in the Bible, or determine that there are "two kinds of people", or discover 4 personality types. Anything can be shoehorned into any kind of pattern if your definition is vague enough and you're willing to stretch the meaning of things hard enough.
Different writers are familiar with different structures and use ones they prefer, bending and modifying them as they wish. Some writers break the rules on purpose. Some writers get high out of their minds and write stream of consciousness novels in a weekend. Any of that can result in a great/famous/successful story. Finding the pattern that fits all of that is only possible if it's so vague that it can fit literally anything, at which point it becomes meaningless.
Plots and story structures can be picked up and used when it's convenient, it's easier to write when you have a paint-by-numbers structure to hang your story upon, but there isn't the one story structure or the six story types, that's silly.