The courts will rule on the question of whether the ADA has been violated. Take a look at the arguments that were made by the parties in A.L. v. Walt Disney World and in the complaint in the Six Flags litigation. The authority cited there is what the courts are considering as precedent.
The previous DAS case (A.L vs WDW) is less applicable because that case was really all about wanting the instant line skip (with multiple uses)... which is what that judgement was on -- finding that accommodation was not a reasonable accommodation for that family. The topics of documentation, registration, etc weren't really addressed because the family wasn't really challenging those elements.
The Six Flags case of course highlights and challenges those questions, and that is where we should expect the first real precedent on the matter (if it ever does goes to court). The main takeaways from AL vs WDW is that unlimited skipping was rejected based on Disney's assertions of it fundamentally impacting the product, that Disney was able to use the impact on other guests to make that claim (and not just other things like additional staffing, etc), and that Disney was able to use the standards of comparing usage data between the populations to make their case.
No one has ruled yet on the reasonableness of requiring documentation for this use case nor has the DOJ addressed it. It's an open field, where only the ADA language itself is the law of the land.
I don't think we disagree as much as you think. I didn't say the DOJ regulations are the end of the story and clearly the matter can be raised. But parties are going to rely heavily on those regulations in arguing what type of accommodations are reasonable, as well as whether a request for documentation would violate the ADA. That's what happens when there is no direct precedent. The courts just don't go off on their own.
But you were making the point that documentation is only referenced three times, and this isn't one of them. My point was, that doesn't constrain the court. The court can rule where the DOJ hasn't yet addressed (or someone can even challenge those). Sure the sides can use the other exceptions (or lack of) to make their arguments, but the court will be forging new ground regardless. It has the ADA language to guide them, as well as prior interpretations... but this spot is a gap. They will have to fill it - if a judgement is ever made.
I do wonder if anyone has the legs to see this through the courts though... or does the Access Board and DOJ get there first? Opinions filed by the DOJ flood this overall topic too.. without necessarily getting to the true Accessibility guidelines.
It's been so long.. maybe it will happen. Which glacial process will get there first?
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