This is my understanding as well, but, OP, ask on the dedicated ticket info thread here for the definitive answer. The ticket thread people know their stuff--more than the CMs at WDW do, and that's not an exaggeration.
OP, if what your two reluctant parkgoers don't like is waiting in line, then the PP is a good idea. But if they just don't like going to or being in a park, then you are about to throw a tremendous amount of $ at something that might not even be of help. PPs for 3 parks for 2 people, depending on when you're going, could cost as much as $1,200 for each person.
These are 2 adults who can fend for themselves. Maybe they'd rather do something not in a park while you're doing the parks.
But, whatever you decide, I'd love to see the results after your trip, and I bet everyone else on this thread would enjoy that too. And it'd be of great help to anyone else with a similar situation.
BTW, Animal Kingdom is the food kingdom of the parks. Enjoy!