This article really misses the point. I fundamentally disagree with the conclusion and think it's actively harmful to neurodivergent people.
They're criticizing academic use of the words "neurodivergent" and "neurodiversity" and effectively demanding that all academic work rigorously categorize people into pre-existing diagnoses. They point to disagreement on what terms mean as a reason to not use the terms. But that's precisely why we need to use the terms, why we need academics studying these things in context.
Remember, it was only 13 years ago that Aspbergers and PPD-NOS were grouped in with Autism Spectrum Disorder. And ADHD & Autism were finally allowed as co-diagnoses. Yes that's right, before 2013 you could not be diagnosed with both ADHD & Autism!
Ultimately, here's the problem. We weren't "done" figuring out neurodivergent diagnoses prior to 2013, we weren't done in 2013, and we aren't done now. Neurodivergence isn't as clear and as clean as these authors seem to think. The existing diagnoses can be very helpful to people, but they also fail a lot of people, and can lead to under- or mis-diagnosis. We need sociologists, neuroscientists, psychologists, and other scholars studying this from many angles.
Maybe one day we'll get to the point where we don't need medical diagnoses for neurodivergent people of all ages to have their needs met, but I don't think we get closer to that day with rigid categorization and unchanging definitions.