I see a couple of problems with the rumored new system:
More able-bodied fakers will see the kiosks, go get a
das and abuse that system that they possibly knew nothing about.
My understanding is that you cannot get the das card at the kiosks. You have to pick them up at Guest Relations in the park. You go to the kiosk to be assigned your return time for a particular ride. If a 'faker' goes to all the trouble of going all the way back to GR to get the card, returns to the kiosk to get a return time for a ride and then sees that they aren't getting any advantage, then I'm pretty sure they won't bother using it. Therefore there is no impact on the lines.
There is no system of verifying disability.
There never has been such a system. That is against the law.
FP may run out much sooner. Or the FP lanes will be packed and the people will be coming back (probably in larger groups), if you get behind them.... plan on waiting.
Why would the FPs run out sooner? The use of a GAC/DAS is completely separate from FPs. People have always been able to use FPs whether they had a GAC or not. This will not change with DAS. So the number of people eligible to use FP is unchanged. The FP lanes are not going to be any more packed than they are now because of the DAS. In fact they could be less congested now if all the 'fakers' are no longer using the special pass. And they should not be returning in larger groups, since the number of people who can accompany a person with the pass is fixed.
More gac/das people will be in standby lanes, making them longer, while waiting for their return time. There is no way to outlaw that.
Again, if a significant percentage of current GAC users are 'fakers', then the percentage of guests using DAS should be much smaller. And since many GAC/DAS users state that they cannot stand in the standby lines for a significant length of time, you may not see this happening. However, since the old 'fakers' will now be doing it the 'hard way', THEY will be now in the standby lines, so the wait times may actually be longer because of that. OTOH, many more rides will now be available for FP+, so this may aid in further reducing standby wait times. Who knows?
More gac/das people will be having meltdowns in the standby lane (that ought to be pleasant) and just in general. Considering we had a raging debate here about bubbles. How do you feel about really really inappropriate behaviors in a confined space? How do you feel about spitting, hitting and screaming, inappropriate other behaviors? I am not condoning it, but I have seen it in parks. I think part of gac was to get the people with behaviors away from others quickly which was a win-win for everyone. I personally would rather someone go ahead of me in line than listen to screaming for 30 minutes, but that's just me.

God help us if the das users all hop in line with their bubble guns!
I must say that this paragraph really doesn't deserve a comment