This!Some one at Disney resorts is thinking. Hey! Can not fully book the higher priced resorts so comp people booking at the lower priced resorts w "upgrades" to the higher priced resorts. A - artificially lowering prices w/o lowering prices. B - the guests will feel special and feel they received a touch of "Magic". C - allow more people to book the lower priced resorts because more rooms will be available. D - give the appearance guests actually feel good booking the higher priced resorts rather than other accommodations.
I used to run a hotel and I would upgrade guests to suites that I knew wouldn't sell that night to open up more lower priced rooms that would sell out. A win/win situation. I get great reviews from happy guests and sell more rooms. Empty rooms don't make any money.