I think the purported issue (I'll say purported because it's based on anecdotal reports that I don't claim to have verified) is that Disney is supposedly using shallow metrics to assess complex issues. They are eyeballing a kid or adult on a video screen and if they're someone who can 'pass' as neurotypical, they probably don't qualify. They're not giving them a rating scale, they're not having a psychologist do a mini assessment, etc. There are many domains that can be affected in things like autism, PDA, ADHD, etc. A child who has precocious language, good adaptive skills, and can mask very well might still have crippling anxiety, or excruciating sensory processing issues, or an explosive temper, etc.
I don't pretend to know what the answer to all this is, I really don't. Because in addition to people with classic "invisible disabilities", there are people who will straight up try to cheat the system, and that's the thing about invisible disabilities - they have the name "invisible" for a reason. They're not something you can have someone take a blood test for, ergo it's easy for people to just lie about them when they're incentivized to do so. But just trying to provide some context regarding the question you asked. I think going to medical documentation might be a start - not a perfect solution, but a start.