It basically boils down to this:
If you select a SINGLE school, AADSAS will get a copy of your scores.
Since it is AADSAS that sends out your application, they're really the only ones who need an official copy. They store it and add it to your application. The scores on your application may not be "official" in that they weren't sent directly to schools by the ADA. However, I have never seen a school say that they wanted an official score sent to them on top of what was sent in the AADSAS application.
For example, I didn't know a single thing about Case when I applied to take the DAT as a sophomore. I obviously didn't select the school. They got my scores with my AADSAS app when I applied, though, and all was well.
Their verbiage is definitely misleading, and I think they should change it. However, for less informed folks, they can make money off of people going back and sending extra reports... and maybe that's why it stays.