DAS is a service for people whose disability prevents them from waiting in lines; it provides an alternate way to wait.
I’m not sure what else he would have been referring to - we travel frequently to WDW with a disabled child using a wheelchair.
All WDW attractions are wheelchair accessible to the point of boarding/attraction (except Tomorrowland Transit Authority, Tom Sawyer Island and Swiss Fsmily Robinson Treehouse).
Most attractions have Mainstream lines, which means the regular line is completely accessible and guests with wheelchairs wait in the line with everyone else. For some, after waiting in the regular line, you will be directed to a different boarding area (usually close to the regular boarding area).
A very few attractions have a different access point for guests using mobility devices / most are in MK and are that way because the line could not be made mainstream. CMs at the entrance will direct you if you need to go somewhere else. In some cases, they may give you a time to return roughly equal to the current wait time. In most cases, power wheelchairs are handled the same as manual wheelchairs.
All shows have wheelchair spots with at least one companion seat.
There are handicapped viewing areas for parades and fireworks; they do fill up quickly and you may need to get there earlier than if you choose to just choose a spot.
Some attractions have wheelchair accessible ride cars, which are also accessible to most power wheelchairs. If you want to stay in your chair, tell the CM at/near the boarding area. Some attractions have ADA ride cars with wider opening doors to make transfers easier. Some also have sliding boards or transfer tiers (bump steps).
There is more information in the disABILITIES FAQs. You can follow the link in my signature or look near the top of this board.
