The whiplash will be is if the system enables people to actually shorten their stay, and discourage longer stays.
Imagine the scenario where the parks get to the point where "Dad" decides.... no way I'm doing the parks without line skip.
Then "Dad" says.. "This thing cost me $1000 a day... I'll do it for 2-3 days, but no more then that.. that's crazy"
Then "Dad" realizes... if this lets us do all the rides quickly, won't I get through everything we want to ride in the park in 1 day? Why do I need to be there for a week?
Now Dad tells the family... "We're gonna do WDW, but only for 3 days... the line skip will get us to all the attractions we want". And all the other forms of entertainment that used to be diversions from the big rides will suffer because they can't all have immediate access to line skip. So the people hooked on line-skip will be more inclined to skip those attractions entirely or only do them if they need a filler.
So now Dad blows his wallet out by buying 2 days full of line-skips, but leaves after 3 days, instead of maybe staying longer. And Disney loses out on the longer stay... or maybe Disney sees it as "I ringed him dry even quicker, and now I got faster turnover"
If Disney enables a system where people can basically do a full day of DPA - those people are never going to want to be in the park without it. That's a double edged sword for Disney and their pricing strategy.