I don't think it's discriminatory to adjust wait times for people with DAS in order to lessen wait times for people with paid access to LL. The problem is that Disney is sending DAS guests through the LL, and that increases the wait times for people who paid to be there.
I'm sorry - but your wrong here. Just like the fact the handicap parking reduces spots and puts regular spots further away disadvantaging 'everyone else' is not a justification to say handicap parking should be allowed to be placed further away as to not create a burden on the others.
Consider the steps in front of City Hall at the Magic Kingdom in WDW. If I can walk up the steps, I can be at the front entrance in a few seconds. If I can't walk up the steps, I have to use the ramp. The ramp requires more physical effort, requires me to travel a longer distance, and it takes more time, but it's still considered equal access because the ramp gets me inside the building.
But the ramp is not introduced as a toll or a way to avoid burdening the 'everyone else'. The ramp is introduced to solve a problem of access. The fact someone may chose to keep stairs too is just a tangent... it means nothing in the sense of what burdens are acceptable.
There's no law that says Disney can't make people with DAS wait longer than people who paid to use the LL. There's no law that says Disney has to give DAS return times that are equal to the standby wait times. If there is a law, I have not been able to find it.
It's right there in title III of the ADA.
(b)
Participation in unequal benefit. A public accommodation shall not afford an individual or class of individuals, on the basis of a disability or disabilities of such individual or class, directly, or through contractual, licensing, or other arrangements, with the opportunity to participate in or benefit from a good, service, facility, privilege, advantage,
or accommodation that is not equal to that afforded to other individuals
And
§ 36.204 Administrative methods.
A public accommodation shall not, directly or through contractual or other arrangements, utilize standards or criteria or methods of administration
that have the effect of discriminating on the basis of disability, or that perpetuate the discrimination of others who are subject to common administrative control.
The issue is queues in theme parks is not an area the DOJ has specifically codified into the accessibility standards, so all interpretation of the law falls back to the interpretation of the wide guiding protections the law sets to provide the disabled. The lack of inclusion doesn't mean they aren't covered, it means there is no Federal Register filed definition of what the gov believes this definition to mean in this particular circumstance. So it relies on a court interpretation of the text of the law.
Trying to say 'we will make you wait longer because you have DAS' is pretty much indefendable. If you said 'it takes longer than going through that line...' because of practical implementation constraints that would be fine. But to say "we're gonna artificially hold you back, so you don't disadvantage someone else" is not a consequence that is defendable. Longer wait because of less dedicated resources... sure.. Longer wait because of a longer walk way? Sure.. Longer wait because I need to ensure you get held back? Not gonna fly...