I understand what the families are saying, that if they take the kid up to the front of the ride, and get a pass for a later time, an autistic kid may pitch a fit about not understanding having to come back later and wanting to ride right now instead of walking away. I do get that. However, I think that could easily be worked around, by scheduling the rides in advance at guest services if they know the child is like that. I think that's something that Disney could easily provide. Although when you think about it, it seems like the regular fastpass+ scheduling in advance would actually work better for the families in these situations than the special services.
I'm not in favor of bringing back the old system, because that will just get abused again. People aren't the same as they were 20 years ago and respectful of the handicapped system- nowadays people just pull anything they can to try to get a little perk like that, so we have to change to something better.
The cardholder does not have to be there when you get the return time, just be there when you do the ride, so sending someone ahead can work. But I wish WDW worked like DLR where they have kiosks instead of having to go to the ride. they could easily use the FP+ kiosks where they have easy access to wait times.