I find it lousy that Tesla hid the 72A option. My guess is that there is currently a limited supply of 72A chargers, and that it would cause delays in deliveries if many people opted for the 72 over the 48. This may bite Tesla in the rear if people who didn't know about the "Easter Egg" way to expose the option take delivery of their car, and later discover that it can't take advantage of the destination HPWCs.
Looking ahead, I wonder if those who ordered it but find they don't need it can swap with those who ordered without knowing about it but find they need it.
I just ran the numbers for a place I frequently visit. 48A would charge it in 8 hours. 72A in 6 hours. When I'm there, there's plenty of days I don't get my full 8 hours of sleep before work. I would literally not make it to work and I'd get fired if I lost even an hour of charging time. But I realize I'm unique. There's lots of people that never go that far: my commute is only 49 miles (15 miles is twisty mountain roads about a thousand or so feet). Even if I take my own example, but just remove the weekend travels, then suddenly any Tesla with about "200 miles rated range" which does a full recharge in 10 hours would be just fine (as long as I had a backup ICE), so the 40A would work. Like I said, if I were someone else. So, it's very conceivable there's lots of people out there for which they don't need 72A but got it on a lark and can swap their cars with those who need it. (As used auto sales between private parties, say, or a CPO deal.)
Edit: oops, I forgot about SuperChargers. If I stopped at one of the SC's (there are two that would require different routes and one would be way out of my way for half of my trips but I could get to), then I could grab dinner on the way to my destination and get about 20 minutes of SC speed charging, for only a quarter hour to one hour overall delay, instead of spending money on gas. That's over half of the battery charged mid-route. That would half the amount of time needed to charge at destination, to only 4 hours with a 48A. That would fit in ok with my habits, with only a modicum of changes.
I think I'll leave this post here to demonstrate the OMG reaction a lot of us get when planning our driving if we consider the purchase of a Tesla X or S. It's often full of simple math, and math doesn't lie, but we make calculation errors and just do things wrong sometimes. And one of the calculations in my case is that maybe the 48A would be just fine, as long as I'm grabbing SuperChargers as often as possible for the non-commute routes. If I ever swing an X or S, here I come, Harris Ranch, Manteca, Gilroy & Monterey (Seaside) SCs!