I thoroughly enjoy this notion and would hope that it stays!
HOWEVER...
If Park After Dark were to replace Surprise Mornings as one of the official "Disney Resort Perks," how would this affect those of us who vacation during Easter and Christmas weeks when the parks are standard open till 11 or midnight? The hours are already extended, and everyone is welcomed. Because that is the case, Guests on property will not get any special benefits for time "alone" in the parks with other Resort Guests who paid the extra money, especially the extra-extra money to vacation during peak holiday times to stay at a Disney Resort.
Therefore, maybe they would extend the park hours till 2am (I did my one and only E-ride this late before) or have the Park close at 10 and Resort Guests only till midnight.
Something like this needs to be considered. And I'm sure it will.
The point is not that we would get extra time in the parks, but rather get extra time with a much reduced crowd load. And I don't know if this would be an option at night during those peak seasons that I and many others vacation as Disney Resort Guests.
Any thought son that?