No, that is not an out.
It means when making the reservation, not that a reservation was made and someone is using it as an 'out' when the guest checks in.
When making a reservation for an accessible room, the system (or the human making the reservation) checks whether or not there are any un-reserved accessible rooms for the dates and type of room that the reservation is for.
If yes, that specific room is set aside for that guest, must be held for that reserving guest and must be removed from the reservation system. (As in the ADA quote I bolded above:
- When a reservation is made for an accessible guest room, the specific accessible guest room reserved must be held for the reserving customer and the room must be removed from the reservation system
That is written into the ADA to prevent overbooking. Could overbooking still occur? Yes, but this makes it very unlikely.
If no, the guest is told there are no rooms that meet their needs for the dates/type of room. The guest then has the choice of trying different dates, a different resort, different requests or different features.
All of this was written into modifications of the ADA to avoid situations where people had made a reservation for a room for a roll in shower (for example), got to their hotel and found that the hotel had overbooked rooms or gave their accessible room to another guest who didn't need it but liked the location better.
It was written because of real life situations like a paraplegic reserving a room with a roll in shower, but by overbooking or giving their room away, they were given a room where they could not get into the bathroom.
Or situation that happened to us many years ago (before the changes) where we arrived very late and had to carry our daughter and her wheelchair up to the second floor at OKW because our accessible room was given to someone who didn't want to climb the steps with their 2 year old's stroller.
People with disabilities who need accessible rooms are given the assurance under the ADA that they will be able to make a reservation and have a reasonable expectation that they will get a room that meets their needs. Without that assurance, many could not travel.
I do believe you have personally walked reservations over for people who had a reservation for an accessible room, but it should be for reasons that the reserved accessible room was not available for unforeseen reasons that make it not available for use. NOT because (for example) there were 11 reservations for one room type, but only 10 rooms and the resort gave the accessible room to one of the other non-disabled guests instead of holding it for the person it was reserved for.
And, finding another room that meets the needs (even if not at the same resort) does meet the ADA requirements, as you mentioned.