I want to see a jury respond after reviewing Disney's promotion of FP+, looking at what customers paid for their WDW accommodations and ticketing -- and reviewing actual breakdowns of wait times for various rides, including FP+ riders and those in standby, as in the type of metrics only known to Disney, along with data associated with availability of FP+ to those specific guests during their visit and those of other high volume FP+ MDE accounts in the same time period.
I don't think a jury is going to look at the opportunity of guest A to use their legitimate FP+ and 3 hours extra in standby lines per day to ride SDMT, Soarin', TOT, PP, etc or decide to wait less and go with Imagination, Living With the Land, Aladdin's Carpets while a review of guest B using their legitimate FP+ and several scammed accounts has entry to multiple attractions listed on Disney's own systems as Tier I in the same amount of time and say guest A and guest B were allowed the same advantages for their price of entry to the park that day.
What concept of law do you think Disney is violating? Personally I'm not sure the case you describe would ever make it to trial. Whether within the TOS or not, Disney didn't handpick who did and didn't use the advantage. I agree that it's good customer practice to equalize experiences to the extent practicable; I'm just curious what you think creates an associated legal obligation in this case.