I feel like the circumstance RE: Nepala are different than they are now.
At Nepala, they were a 5th place ID team that was squarely U.S. No. 2. Now they're three-time world medalists and for now a pretty strong U.S. No. 1. And I'd also argue that the Nepala/Fix You experience may have made them feel the opposite of doing a lot of senior Bs -- that they would be better off come prepared with a program they had full-confidence and belief in, which means investing time in those programs rather than spending valuable training time going to competitions.
I agree that they like the element of surprise. I remember that Alex and Maia were even very secretive of who did their costumes (it wasn't one of the typical skating costumes types but someone in LA). And I feel they are a more confident team now then they were a few years ago.
ETA: I looked back on the Nepala video -- and yes, they looked really tentative there. It was pretty obvious while they liked the program, they weren't 100 percent on it. I wouldn't be surprised if with their current FD, they've tried out a bunch of different versions to ensure they can come out swinging when the first GP came around.
Also, I feel like the skating gods are having them go back to their low point competitions as a way to have new more positive memories. Rostelecom Cup is one of just two GP where they have not medaled in (they've never competed at TEB, TdF or it's other versions) and their one appearance five years ago is the only time in their whole GP career (other than GPF) they were off the podium.