My guess they will extend it, though I doubt they will have this in the fall with the holiday parties already taking up a lot of nights. But who knows.
I can't see them scrapping something so quickly. It hasn't had time to catch on. If people had more noticed than a month, I would bet more people would sign up.
Or maybe they need a slight price adjustment. I feel there is a demand for this sorta thing --- to experience an EMPTY park .. to experience all the rides with NO lines .. to be in the park REALLY late at night.
Just because the first few events weren't sellouts isn't telling. I mean word has BARELY gotten out to the general public. People who already had their April vacations planned probably didn't have enough notice to even consider it. Travel agents haven't had time to promote it, etc. How many people going to WDW right now don't even know this is available?
I see this as a way for Disney to test having a hard-ticket night event during the first 8 months of the year.
I definitely see the Early Morning Magic thing to be way more popular than this (and they will probably extend this to other parks). They would be silly to not offer a Askerhus breakfast package that gives you early access to A&E and the new ride.