I suspect this is similar - rich parents are doing anything for an edge in their child's education and can get any diagnosis they desire. It's an unfair system.
I was diagnosed in my 40s with ASD and ADHD. It may have been helpful to know earlier (though I could debate both sides of that), but I didn’t need any special classes or helpers that would take resources from others. I’m wondering if some kids are saying they need this stuff to justify the condition or to play up the sympathy, to make the condition their personality.
In a highly competitive environment like Stanford, isn't it more likely that it's to get more time on tests -> better grades -> higher paying job?
If they need all that extra time, the university on the degree might get them some extra money out of the gate, but I have to imagine it will work against them if they are slow and are always asking for extra time to complete projects. That’s not going to get them promoted and they will stagnate. I’ve also never had any job ask me about my grades.