The Florida info states:
This would be at the heart of any argument against how they are doing things, one could easily argue that the distance alone makes it not an "easily accessible route"
As for California, here is a link:
https://adata.org/factsheet/parking
The applicable part here is:
The sports stadium would be an apt example and there are ways that Disney could move the ADA parking spaces closer to the entrance by doing things like moving the tram route to drop off behind the ADA parking spaces.
In California, shortest accessible route has been further defined by local plan checkers as need to place the parking lots as close to the applicable buildings/entrances as is possible, they have made various businesses move their entire parking lots as a result.
Now, the alternative that Disney has been given at the hotels in California is that they can either make the parking closer or offer valet parking at self parking prices for those that have ADA placards/plates. Since Disney doesn't yet offer valet parking at the theme parks (but you can bet they will given that many other theme parks are starting to do so), they don't have that option yet.