We haven't seen it in action yet.
Having been through the DAS process in the past, I'll tell you a few things that I've been able to do. On the pre-registration conversation you can approve any number of people to be attached to the DAS with the disabled guest. Under the old rules, once you're in the park, you can request a DAS for the disabled guest and 5 additional guests. I suspect none of that will change other than the switch from 5 guests to 3.
Then fast forward to being in the park, and my in laws join us for a day. We now have 7 ticketed guests but can only book the DAS for a particular ride for 6 guests. So a trip to a blue umbrella allows us to add an additional guest once we're in the park.
I'm sure some people on here will look down on that, and up thread I posted that the previous 6 person cap was a soft cap. They've already hedged their bets on this that they have the ability to move off the 4 person cap. What we don't know is if that is dictated as part of the pre-registration process or if CMs in the park have the ability to manipulate the cap.
We're 84 pages deep on this and I suspect the only material change of procedure will be the reduction of the soft cap from 6 guests to 4. It will curb usage for a short period of time and then usage will continue to trend higher.
If they want to fundamentally curb usage of DAS, they need to eliminate the costs associated with Genie+ and actually enforce their own rules and threats.