Any chance you can use Star Buck gift cards at ‘Star Bucks’ in WDW?
Yes, I use my Starbucks card. You cannot redeem rewards but you can earn them too.
Quick addition to that: I’ve seen around the web (and confirmed on the app) that the StarBucks in Disney Springs you CAN redeem your rewards at as those two are company-owned stores instead of just a “branded one” like in the parks (friggin confusing that whole “branded, but not really a Starbucks” situation). So if you happen to go on your “birthday”…head over to Disney Springs and grab your freebie.
But the ones in the parks themselves seem to be just as @PrincipalTinker said. (Which explains my confusion earlier as I had redeemed my reward at the Disney Springs one and thought they were all the same).