My $100,000 initial Aulani DVC investment and many $1000’s in annual dues say otherwise.
Next time you’re there, read the sign for the cups:
REFILLABLE MUGS TO BE USED AT RESORT REFILLABLE MUG STATIONS FOR UNLIMITED SOFT DRINHS, TEA, & COFFEE
The sign would say something like during your current stay or similar, or they would chip them like other resorts if they wanted to limit them. Also ask the workers in Ulu Café and they will say the same. We asked again once they started selling the more expensive stainless ones and got the same answer as always; ok to bring back next time.